1.6 complex numbers
TRANSCRIPT
![Page 1: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/1.jpg)
Complex Numbers
![Page 2: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/2.jpg)
Complex NumbersBecause the square of any real number can't be negative, the equation x2 = –1 does not have any solution.
![Page 3: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/3.jpg)
Complex NumbersBecause the square of any real number can't be negative, the equation x2 = –1 does not have any solution. We make up a new imaginary number –1to be a solution of this equation
![Page 4: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/4.jpg)
Complex NumbersBecause the square of any real number can't be negative, the equation x2 = –1 does not have any solution. We make up a new imaginary number –1 ↔ ito be a solution of this equation and we name it as “ i ”,
![Page 5: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/5.jpg)
Complex NumbersBecause the square of any real number can't be negative, the equation x2 = –1 does not have any solution. We make up a new imaginary number –1 ↔ ito be a solution of this equation and we name it as “ i ”, i.e.
(±i)2 = –1
![Page 6: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/6.jpg)
Complex Numbers
Using i, the “solutions” of the equations of the form
Because the square of any real number can't be negative, the equation x2 = –1 does not have any solution. We make up a new imaginary number –1 ↔ ito be a solution of this equation and we name it as “ i ”, i.e.
(±i)2 = –1
x2 = –rare x = ± ir
![Page 7: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/7.jpg)
Complex Numbers
Using i, the “solutions” of the equations of the form
Example A. Solve x2 + 49 = 0 using imaginary numbers.
Because the square of any real number can't be negative, the equation x2 = –1 does not have any solution. We make up a new imaginary number –1 ↔ ito be a solution of this equation and we name it as “ i ”, i.e.
(±i)2 = –1
x2 = –rare x = ± ir
![Page 8: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/8.jpg)
Complex Numbers
Using i, the “solutions” of the equations of the form
Example A. Solve x2 + 49 = 0 using imaginary numbers. Using the square-root method:x2 + 49 = 0 → x2 = –49
Because the square of any real number can't be negative, the equation x2 = –1 does not have any solution. We make up a new imaginary number –1 ↔ ito be a solution of this equation and we name it as “ i ”, i.e.
(±i)2 = –1
x2 = –rare x = ± ir
![Page 9: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/9.jpg)
Complex Numbers
Using i, the “solutions” of the equations of the form
Example A. Solve x2 + 49 = 0 using imaginary numbers. Using the square-root method:x2 + 49 = 0 → x2 = –49 sox = ±–49
Because the square of any real number can't be negative, the equation x2 = –1 does not have any solution. We make up a new imaginary number –1 ↔ ito be a solution of this equation and we name it as “ i ”, i.e.
(±i)2 = –1
x2 = –rare x = ± ir
![Page 10: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/10.jpg)
Complex Numbers
Using i, the “solutions” of the equations of the form
Example A. Solve x2 + 49 = 0 using imaginary numbers. Using the square-root method:x2 + 49 = 0 → x2 = –49 sox = ±–49 x = ±49–1 x = ±7i
Because the square of any real number can't be negative, the equation x2 = –1 does not have any solution. We make up a new imaginary number –1 ↔ ito be a solution of this equation and we name it as “ i ”, i.e.
(±i)2 = –1
x2 = –rare x = ± ir
![Page 11: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/11.jpg)
A complex number is a number of the form a + biwhere a and b are real numbers,
Complex Numbers
![Page 12: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/12.jpg)
A complex number is a number of the form a + biwhere a and b are real numbers, a is called the real part
Complex Numbers
![Page 13: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/13.jpg)
A complex number is a number of the form a + biwhere a and b are real numbers, a is called the real part and bi is called the imaginary part of the complex number.
Complex Numbers
![Page 14: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/14.jpg)
A complex number is a number of the form a + biwhere a and b are real numbers, a is called the real part and bi is called the imaginary part of the complex number.
Complex Numbers
Example B. 5 – 3i, 6i, –17 are complex numbers.
![Page 15: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/15.jpg)
A complex number is a number of the form a + biwhere a and b are real numbers, a is called the real part and bi is called the imaginary part of the complex number.
Complex Numbers
Example B. 5 – 3i, 6i, –17 are complex numbers. The imaginary part of 5 – 3i is –3i.
![Page 16: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/16.jpg)
A complex number is a number of the form a + biwhere a and b are real numbers, a is called the real part and bi is called the imaginary part of the complex number.
Complex Numbers
Example B. 5 – 3i, 6i, –17 are complex numbers. The imaginary part of 5 – 3i is –3i. The real part of 6i is 0.
![Page 17: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/17.jpg)
A complex number is a number of the form a + biwhere a and b are real numbers, a is called the real part and bi is called the imaginary part of the complex number.
Complex Numbers
Example B. 5 – 3i, 6i, –17 are complex numbers. The imaginary part of 5 – 3i is –3i. The real part of 6i is 0.Any real number a is also a complex because a = a + 0i hence –17 = –17 + 0i.
![Page 18: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/18.jpg)
A complex number is a number of the form a + biwhere a and b are real numbers, a is called the real part and bi is called the imaginary part of the complex number
Example B. 5 – 3i, 6i, –17 are complex numbers. The imaginary part of 5 – 3i is –3i. The real part of 6i is 0.Any real number a is also a complex because a = a + 0i hence –17 = –17 + 0i.
Complex Numbers
(Addition and subtraction of complex numbers)Treat the "i" as a variable when adding or subtracting complex numbers.
![Page 19: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/19.jpg)
A complex number is a number of the form a + biwhere a and b are real numbers, a is called the real part and bi is called the imaginary part of the complex number
Complex Numbers
(Addition and subtraction of complex numbers)Treat the "i" as a variable when adding or subtracting complex numbers. Example C.(7 + 4i) + (5 – 3i)
Example B. 5 – 3i, 6i, –17 are complex numbers. The imaginary part of 5 – 3i is –3i. The real part of 6i is 0.Any real number a is also a complex because a = a + 0i hence –17 = –17 + 0i.
![Page 20: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/20.jpg)
A complex number is a number of the form a + biwhere a and b are real numbers, a is called the real part and bi is called the imaginary part of the complex number
Complex Numbers
(Addition and subtraction of complex numbers)Treat the "i" as a variable when adding or subtracting complex numbers. Example C.(7 + 4i) + (5 – 3i) = 7 + 4i + 5 – 3i
Example B. 5 – 3i, 6i, –17 are complex numbers. The imaginary part of 5 – 3i is –3i. The real part of 6i is 0.Any real number a is also a complex because a = a + 0i hence –17 = –17 + 0i.
![Page 21: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/21.jpg)
A complex number is a number of the form a + biwhere a and b are real numbers, a is called the real part and bi is called the imaginary part of the complex number
Complex Numbers
(Addition and subtraction of complex numbers)Treat the "i" as a variable when adding or subtracting complex numbers. Example C.(7 + 4i) + (5 – 3i) = 7 + 4i + 5 – 3i = 12 + i
Example B. 5 – 3i, 6i, –17 are complex numbers. The imaginary part of 5 – 3i is –3i. The real part of 6i is 0.Any real number a is also a complex because a = a + 0i hence –17 = –17 + 0i.
![Page 22: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/22.jpg)
A complex number is a number of the form a + biwhere a and b are real numbers, a is called the real part and bi is called the imaginary part of the complex number
Complex Numbers
(Addition and subtraction of complex numbers)Treat the "i" as a variable when adding or subtracting complex numbers. Example C.(7 + 4i) + (5 – 3i) = 7 + 4i + 5 – 3i = 12 + i(7 + 4i) – (5 – 3i)
Example B. 5 – 3i, 6i, –17 are complex numbers. The imaginary part of 5 – 3i is –3i. The real part of 6i is 0.Any real number a is also a complex because a = a + 0i hence –17 = –17 + 0i.
![Page 23: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/23.jpg)
A complex number is a number of the form a + biwhere a and b are real numbers, a is called the real part and bi is called the imaginary part of the complex number
Complex Numbers
(Addition and subtraction of complex numbers)Treat the "i" as a variable when adding or subtracting complex numbers. Example C.(7 + 4i) + (5 – 3i) = 7 + 4i + 5 – 3i = 12 + i(7 + 4i) – (5 – 3i) = 7 + 4i – 5 + 3i
Example B. 5 – 3i, 6i, –17 are complex numbers. The imaginary part of 5 – 3i is –3i. The real part of 6i is 0.Any real number a is also a complex because a = a + 0i hence –17 = –17 + 0i.
![Page 24: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/24.jpg)
A complex number is a number of the form a + biwhere a and b are real numbers, a is called the real part and bi is called the imaginary part of the complex number
Complex Numbers
(Addition and subtraction of complex numbers)Treat the "i" as a variable when adding or subtracting complex numbers. Example C.(7 + 4i) + (5 – 3i) = 7 + 4i + 5 – 3i = 12 + i(7 + 4i) – (5 – 3i) = 7 + 4i – 5 + 3i = 2 + 7i
Example B. 5 – 3i, 6i, –17 are complex numbers. The imaginary part of 5 – 3i is –3i. The real part of 6i is 0.Any real number a is also a complex because a = a + 0i hence –17 = –17 + 0i.
![Page 25: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/25.jpg)
(Multiplication of complex numbers)Complex Numbers
![Page 26: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/26.jpg)
(Multiplication of complex numbers)To multiply complex numbers, use FOIL, then set i2 to be (-1) and simplify the result.
Complex Numbers
![Page 27: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/27.jpg)
(Multiplication of complex numbers)To multiply complex numbers, use FOIL, then set i2 to be (-1) and simplify the result.
Complex Numbers
Example D. (4 – 3i)(2 + 7i)
![Page 28: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/28.jpg)
(Multiplication of complex numbers)To multiply complex numbers, use FOIL, then set i2 to be (-1) and simplify the result.
Complex Numbers
Example D. (4 – 3i)(2 + 7i) FOIL = 8 – 6i + 28i – 21i2
![Page 29: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/29.jpg)
(Multiplication of complex numbers)To multiply complex numbers, use FOIL, then set i2 to be (-1) and simplify the result.
Complex Numbers
Example D. (4 – 3i)(2 + 7i) FOIL = 8 – 6i + 28i – 21i2 set i2 = (-1) = 8 – 6i + 28i + 21
![Page 30: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/30.jpg)
(Multiplication of complex numbers)To multiply complex numbers, use FOIL, then set i2 to be (-1) and simplify the result.
Complex Numbers
Example D. (4 – 3i)(2 + 7i) FOIL = 8 – 6i + 28i – 21i2 set i2 = (-1) = 8 – 6i + 28i + 21 = 29 + 22i
![Page 31: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/31.jpg)
(Multiplication of complex numbers)To multiply complex numbers, use FOIL, then set i2 to be (-1) and simplify the result.
Complex Numbers
Example D. (4 – 3i)(2 + 7i) FOIL = 8 – 6i + 28i – 21i2 set i2 = (-1) = 8 – 6i + 28i + 21 = 29 + 22i The conjugate of (a + bi) is (a – bi) and vice–versa.
![Page 32: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/32.jpg)
(Multiplication of complex numbers)To multiply complex numbers, use FOIL, then set i2 to be (-1) and simplify the result.
Complex Numbers
Example D. (4 – 3i)(2 + 7i) FOIL = 8 – 6i + 28i – 21i2 set i2 = (-1) = 8 – 6i + 28i + 21 = 29 + 22i The conjugate of (a + bi) is (a – bi) and vice–versa.The most important complex number multiplication formula is the product of a pair of conjugate numbers.
![Page 33: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/33.jpg)
(Multiplication of complex numbers)To multiply complex numbers, use FOIL, then set i2 to be (-1) and simplify the result.
Complex Numbers
Example D. (4 – 3i)(2 + 7i) FOIL = 8 – 6i + 28i – 21i2 set i2 = (-1) = 8 – 6i + 28i + 21 = 29 + 22i
(Conjugate Multiplication)
The conjugate of (a + bi) is (a – bi) and vice–versa.The most important complex number multiplication formula is the product of a pair of conjugate numbers.
![Page 34: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/34.jpg)
(Multiplication of complex numbers)To multiply complex numbers, use FOIL, then set i2 to be (-1) and simplify the result.
Complex Numbers
Example D. (4 – 3i)(2 + 7i) FOIL = 8 – 6i + 28i – 21i2 set i2 = (-1) = 8 – 6i + 28i + 21 = 29 + 22i
(Conjugate Multiplication) The nonzero conjugate product is(a + bi)(a – bi) = a2 + b2 which is always positive.
The conjugate of (a + bi) is (a – bi) and vice–versa.The most important complex number multiplication formula is the product of a pair of conjugate numbers.
![Page 35: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/35.jpg)
(Multiplication of complex numbers)To multiply complex numbers, use FOIL, then set i2 to be (-1) and simplify the result.
Complex Numbers
Example D. (4 – 3i)(2 + 7i) FOIL = 8 – 6i + 28i – 21i2 set i2 = (-1) = 8 – 6i + 28i + 21 = 29 + 22i
Example E.
(4 – 3i)(4 + 3i)
The conjugate of (a + bi) is (a – bi) and vice–versa.The most important complex number multiplication formula is the product of a pair of conjugate numbers. (Conjugate Multiplication) The nonzero conjugate product is (a + bi)(a – bi) = a2 + b2 which is always positive.
![Page 36: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/36.jpg)
(Multiplication of complex numbers)To multiply complex numbers, use FOIL, then set i2 to be (-1) and simplify the result.
Complex Numbers
Example D. (4 – 3i)(2 + 7i) FOIL = 8 – 6i + 28i – 21i2 set i2 = (-1) = 8 – 6i + 28i + 21 = 29 + 22i
Example E.
(4 – 3i)(4 + 3i) = 42 + 32 = 25
The conjugate of (a + bi) is (a – bi) and vice–versa.The most important complex number multiplication formula is the product of a pair of conjugate numbers. (Conjugate Multiplication) The nonzero conjugate product is(a + bi)(a – bi) = a2 + b2 which is always positive.
![Page 37: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/37.jpg)
(Multiplication of complex numbers)To multiply complex numbers, use FOIL, then set i2 to be (-1) and simplify the result.
Complex Numbers
Example D. (4 – 3i)(2 + 7i) FOIL = 8 – 6i + 28i – 21i2 set i2 = (-1) = 8 – 6i + 28i + 21 = 29 + 22i
Example E.
(4 – 3i)(4 + 3i) = 42 + 32 = 25(5 – 7i)(5 + 7i)
The conjugate of (a + bi) is (a – bi) and vice–versa.The most important complex number multiplication formula is the product of a pair of conjugate numbers. (Conjugate Multiplication) The nonzero conjugate product is(a + bi)(a – bi) = a2 + b2 which is always positive.
![Page 38: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/38.jpg)
(Multiplication of complex numbers)To multiply complex numbers, use FOIL, then set i2 to be (-1) and simplify the result.
Complex Numbers
Example D. (4 – 3i)(2 + 7i) FOIL = 8 – 6i + 28i – 21i2 set i2 = (-1) = 8 – 6i + 28i + 21 = 29 + 22i
Example E.
(4 – 3i)(4 + 3i) = 42 + 32 = 25(5 – 7i)(5 + 7i) = (5)2 + 72
The conjugate of (a + bi) is (a – bi) and vice–versa.The most important complex number multiplication formula is the product of a pair of conjugate numbers. (Conjugate Multiplication) The nonzero conjugate product is(a + bi)(a – bi) = a2 + b2 which is always positive.
![Page 39: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/39.jpg)
(Multiplication of complex numbers)To multiply complex numbers, use FOIL, then set i2 to be (-1) and simplify the result.
Complex Numbers
Example D. (4 – 3i)(2 + 7i) FOIL = 8 – 6i + 28i – 21i2 set i2 = (-1) = 8 – 6i + 28i + 21 = 29 + 22i
Example E.
(4 – 3i)(4 + 3i) = 42 + 32 = 25(5 – 7i)(5 + 7i) = (5)2 + 72 = 54
The conjugate of (a + bi) is (a – bi) and vice–versa.The most important complex number multiplication formula is the product of a pair of conjugate numbers. (Conjugate Multiplication) The nonzero conjugate product is(a + bi)(a – bi) = a2 + b2 which is always positive.
![Page 40: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/40.jpg)
Complex Numbers(Division of Complex Numbers)
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Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
![Page 42: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/42.jpg)
Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i 4 + 3i Example F. Simplify
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Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i 4 + 3i Example F. Simplify
Multiply the conjugate of the denominator (4 – 3i) to the top and the bottom.(3 – 2i) (4 + 3i)
![Page 44: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/44.jpg)
Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i 4 + 3i Example F. Simplify
Multiply the conjugate of the denominator (4 – 3i) to the top and the bottom.(3 – 2i) (4 + 3i)
= (4 – 3i) (4 – 3i)
*
![Page 45: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/45.jpg)
Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i 4 + 3i Example F. Simplify
Multiply the conjugate of the denominator (4 – 3i) to the top and the bottom.(3 – 2i) (4 + 3i)
= (4 – 3i) (4 – 3i)
* 42 + 32
![Page 46: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/46.jpg)
Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i Example F. SimplifyMultiply the conjugate of the denominator (4 – 3i) to the top and the bottom.(3 – 2i) (4 + 3i)
= (4 – 3i) (4 – 3i)
* 42 + 32 = 25
4 + 3i
![Page 47: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/47.jpg)
Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i 4 + 3i Example F. Simplify
Multiply the conjugate of the denominator (4 – 3i) to the top and the bottom.(3 – 2i) (4 + 3i)
= (4 – 3i) (4 – 3i)
* 42 + 32 = 2512 – 8i – 9i + 6i2
![Page 48: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/48.jpg)
Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i 4 + 3i Example F. Simplify
Multiply the conjugate of the denominator (4 – 3i) to the top and the bottom.(3 – 2i) (4 + 3i)
= (4 – 3i) (4 – 3i)
* 42 + 32 = 2512 – 8i – 9i + 6i2
–6
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Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i 4 + 3i Example F. Simplify
Multiply the conjugate of the denominator (4 – 3i) to the top and the bottom.(3 – 2i) (4 + 3i)
= (4 – 3i) (4 – 3i)
* 42 + 32 = 2512 – 8i – 9i + 6i2
–6
6 – 17i = 256
2517i –
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Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i 4 + 3i Example F. Simplify
Multiply the conjugate of the denominator (4 – 3i) to the top and the bottom.(3 – 2i) (4 + 3i)
= (4 – 3i) (4 – 3i)
* 42 + 32 = 2512 – 8i – 9i + 6i2
–6
6 – 17i = 256
2517i –
Using the quadratic formula, we can solve all 2nd degree equations and obtain their complex number solutions.
![Page 51: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/51.jpg)
Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i 4 + 3i Example F. Simplify
Multiply the conjugate of the denominator (4 – 3i) to the top and the bottom.(3 – 2i) (4 + 3i)
= (4 – 3i) (4 – 3i)
* 42 + 32 = 2512 – 8i – 9i + 6i2
–6
6 – 17i = 256
2517i –
Example G. Solve 2x2 – 2x + 3 = 0 and simplify the answers.
Using the quadratic formula, we can solve all 2nd degree equations and obtain their complex number solutions.
![Page 52: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/52.jpg)
Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i 4 + 3i Example F. Simplify
Multiply the conjugate of the denominator (4 – 3i) to the top and the bottom.(3 – 2i) (4 + 3i)
= (4 – 3i) (4 – 3i)
* 42 + 32 = 2512 – 8i – 9i + 6i2
–6
6 – 17i = 256
2517i –
Example G. Solve 2x2 – 2x + 3 = 0 and simplify the answers.To find b2 – 4ac first: a = 2, b = –2, c = 3,
Using the quadratic formula, we can solve all 2nd degree equations and obtain their complex number solutions.
![Page 53: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/53.jpg)
Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i 4 + 3i Example F. Simplify
Multiply the conjugate of the denominator (4 – 3i) to the top and the bottom.(3 – 2i) (4 + 3i)
= (4 – 3i) (4 – 3i)
* 42 + 32 = 2512 – 8i – 9i + 6i2
–6
6 – 17i = 256
2517i –
Example G. Solve 2x2 – 2x + 3 = 0 and simplify the answers.To find b2 – 4ac first: a = 2, b = –2, c = 3, so b2 – 4ac = –20.
Using the quadratic formula, we can solve all 2nd degree equations and obtain their complex number solutions.
![Page 54: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/54.jpg)
Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i 4 + 3i Example F. Simplify
Multiply the conjugate of the denominator (4 – 3i) to the top and the bottom.(3 – 2i) (4 + 3i)
= (4 – 3i) (4 – 3i)
* 42 + 32 = 2512 – 8i – 9i + 6i2
–6
6 – 17i = 256
2517i –
Example G. Solve 2x2 – 2x + 3 = 0 and simplify the answers.To find b2 – 4ac first: a = 2, b = –2, c = 3, so b2 – 4ac = –20.
x = 2 ± –204
Using the quadratic formula, we can solve all 2nd degree equations and obtain their complex number solutions.
Hence
![Page 55: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/55.jpg)
Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i 4 + 3i Example F. Simplify
Multiply the conjugate of the denominator (4 – 3i) to the top and the bottom.(3 – 2i) (4 + 3i)
= (4 – 3i) (4 – 3i)
* 42 + 32 = 2512 – 8i – 9i + 6i2
–6
6 – 17i = 256
2517i –
Example G. Solve 2x2 – 2x + 3 = 0 and simplify the answers.To find b2 – 4ac first: a = 2, b = –2, c = 3, so b2 – 4ac = –20.
x = 2 ± –204 = 2 ± 2–5
4
Using the quadratic formula, we can solve all 2nd degree equations and obtain their complex number solutions.
Hence
![Page 56: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/56.jpg)
Complex Numbers(Division of Complex Numbers)To divide complex numbers, we write the division as a fraction, then multiply the top and the bottom of the fraction by the conjugate of the denominator.
3 – 2i 4 + 3i Example F. Simplify
Multiply the conjugate of the denominator (4 – 3i) to the top and the bottom.(3 – 2i) (4 + 3i)
= (4 – 3i) (4 – 3i)
* 42 + 32 = 2512 – 8i – 9i + 6i2
–6
6 – 17i = 256
2517i –
Example G. Solve 2x2 – 2x + 3 = 0 and simplify the answers.To find b2 – 4ac first: a = 2, b = –2, c = 3, so b2 – 4ac = –20.
x = 2 ± –204 = 2 ± 2–5
4 = 2(1 ± i5)4 = 1 ± i5
2
Using the quadratic formula, we can solve all 2nd degree equations and obtain their complex number solutions.
Hence
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Powers of i
The powers of i go in a cycle as shown below:
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The powers of i go in a cycle as shown below:
i
-1 = i2
Powers of i
![Page 59: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/59.jpg)
The powers of i go in a cycle as shown below:
i
-1 = i2
-i = i3
Powers of i
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The powers of i go in a cycle as shown below:
i
-1 = i2
-i = i3
1 = i4
Powers of i
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The powers of i go in a cycle as shown below:
i = i5
-1 = i2
-i = i3
1 = i4
Powers of i
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The powers of i go in a cycle as shown below:
i = i5
-1 = i2 = i6 ..
-i = i3
1 = i4
Powers of i
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The powers of i go in a cycle as shown below:
i = i5
-1 = i2 = i6 ..
-i = i3 = i7 ..
1 = i4
Powers of i
![Page 64: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/64.jpg)
The powers of i go in a cycle as shown below:
i = i5
-1 = i2 = i6 ..
-i = i3 = i7 ..
1 = i4 = i8 ..
Powers of i
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The powers of i go in a cycle as shown below:
i = i5 = i9 ..
-1 = i2 = i6 ..
-i = i3 = i7 ..
1 = i4 = i8 ..
Powers of i
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The powers of i go in a cycle as shown below:
i = i5 = i9 ..
-1 = i2 = i6 ..
-i = i3 = i7 ..
1 = i4 = i8 ..
Example H. Simplify i59
Powers of i
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The powers of i go in a cycle as shown below:
i = i5 = i9 ..
-1 = i2 = i6 ..
-i = i3 = i7 ..
1 = i4 = i8 ..
Example H. Simplify i59
59 = 4*14 + 3,
Powers of i
![Page 68: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/68.jpg)
The powers of i go in a cycle as shown below:
i = i5 = i9 ..
-1 = i2 = i6 ..
-i = i3 = i7 ..
1 = i4 = i8 ..
Example H. Simplify i59
59 = 4*14 + 3, hence i59 = i4*14+3
Powers of i
![Page 69: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/69.jpg)
The powers of i go in a cycle as shown below:
i = i5 = i9 ..
-1 = i2 = i6 ..
-i = i3 = i7 ..
1 = i4 = i8 ..
Example H. Simplify i59
59 = 4*14 + 3, hence i59 = i4*14+3 = i4*14+3
Powers of i
![Page 70: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/70.jpg)
The powers of i go in a cycle as shown below:
i = i5 = i9 ..
-1 = i2 = i6 ..
-i = i3 = i7 ..
1 = i4 = i8 ..
Example H. Simplify i59
59 = 4*14 + 3, hence i59 = i4*14+3 = i4*14+3 = (i4)14 i3
Powers of i
![Page 71: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/71.jpg)
The powers of i go in a cycle as shown below:
i = i5 = i9 ..
-1 = i2 = i6 ..
-i = i3 = i7 ..
1 = i4 = i8 ..
Example H. Simplify i59
59 = 4*14 + 3, hence i59 = i4*14+3 = i4*14+3 = (i4)14 i3 = 114 i3
Powers of i
![Page 72: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/72.jpg)
The powers of i go in a cycle as shown below:
i = i5 = i9 ..
-1 = i2 = i6 ..
-i = i3 = i7 ..
1 = i4 = i8 ..
Example H. Simplify i59
59 = 4*14 + 3, hence i59 = i4*14+3 = i4*14+3 = (i4)14 i3 = 114 i3 = i3 = -i
Powers of i
![Page 73: 1.6 complex numbers](https://reader035.vdocuments.net/reader035/viewer/2022062901/58f2f4e21a28ab0c7d8b45dd/html5/thumbnails/73.jpg)
Complex NumbersIn what sense are the complex numbers, numbers?Real numbers are physically measurable quantities (or the lack of such quantities in the case of the negative numbers).Theoretically, we can forever improve upon the construction of a stick with length exactly 2. But how do we make a stick of length 3i, or a cookie that weigh 3i oz? Well, we can’t. Imaginary numbers and complex numbers in general are not physically measurable in the traditional sense. Only the real numbers, which are a part of the complex numbers, are tangible in traditional sense.
Complex numbers are directional measurements. They keep track of measurements and directions, i.e. how much and in what direction (hence the two–component form of the complex numbers). Google the terms “complex numbers, 2D vectors” for further information.
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Complex NumbersExercise A. Write the complex numbers in i’s. Combine the following expressions. 1. 2 – 2i + 3 + √–4 2. 4 – 5i – (4 – √–9) 3. 3 + 2i + (4 – i√5) 4. 4 – 2i + (–6 + i√3) 5. 4 – √–25 – (9 – √–
16) 6. 11 – 9i + (–7 + i√12) 7. ½ – (√–49)/3 – (3/4 – √–16) Exercise B. Do by inspection.8. (1 – 2i)(1 + 2i) 9. (1 + 3i)(1 – 3i) 10. (2 + 3i)(2 – 3i)11. (3 – 4i)(3 + 4i) 12. (9 + i√3)(9 – √3i) 13. (7 – i√5)(7 + i√5)14. (9 + i√3) (7 – i√5)(9 – i√3) (7 + i√5)15. (√3 + i√3) (√7 – i√5)(√3 – i√3)(√7 + i√5)Exercise C. Expand and simplify.16. (1 – 3i)(1 + 2i) 17. (2 + 3i)(1 – 3i) 18. (2 + 3i)(3 – 2i)19. (4 – 3i)(3 – 4i) 20. (5 + 3i)(5 + 3i) 21. (1 – i)2
22. (2 + 3i)2 23. (5 + 2i)2
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Complex NumbersExercise D. Divide by rationalizing the denominators.
2 + 3ii24. 3 – 4i
i25. 3 – 4ii26.
1 + i1 – i27. 2 – i
3 – i28. 3 – 2i2 + i29.
2 + 3i2 – 3i30. 3 – 4i
3 – 2i31. 3 – 4i2 + 5i32.
33. Is there a difference between √4i and 2i?