mean value theorem for integrals

7
Mean Value Theorem for Integrals b a f x dx f c b a If f(x) is continuous on [a, b], then there exists a number x=c in [a, b] such that a b c f(c ) For continuous functions, there must be some average value such that the area under the original curve is equal to the average value multiplied by the length from x=a to x=b.

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Mean Value Theorem for Integrals. If f(x) is continuous on [a, b], then there exists a number x=c in [a, b] such that. For continuous functions, there must be some average value such that the area under the original curve is equal to the average value multiplied by the length from x=a to x=b. - PowerPoint PPT Presentation

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Page 1: Mean Value Theorem for Integrals

Mean Value Theorem for Integrals

b

a

f x dx f c b a

If f(x) is continuous on [a, b], then there exists a number x=c in [a, b] such that

a bc

f(c)

For continuous functions, there must be some average value such that the area under the original curve is equal to the average value multiplied by the length from x=a to x=b.

Page 2: Mean Value Theorem for Integrals

Average Value of a function, f(x)

1 b

a

Avg f c f xb a

Examples: Find the point(s) on the graph that represents the average value of the function.2( ) 3 2 [1, 4]f x x x on 1

. 4

2

1

13 2

4 1f c x x dx

43 2

1

1

3f c x x

164 16 1 1

3f c 1

48 163

Page 3: Mean Value Theorem for Integrals

2.

3

91, 3f x on

x

3

3

1

19

2f c x dx

3

21

1 9

2 2x

23 2 16x x 23 2 16 0x x

3 8 2 0x x 8, 23

x 8,163

Find the point(s) on the graph that represents the average value of the function.

Page 4: Mean Value Theorem for Integrals

1 9 9

2 18 2

14 2

2

3

92

x

3 9

2x

39

1.652

x

1.65, 2

Page 5: Mean Value Theorem for Integrals

b

a

f x dx Area under curve

x

a

f t dt Accumulation functionFunction that finds area under curve at any value of x.

0

cosx

t dt0sinxt

sin sin 0x

sin x

Page 6: Mean Value Theorem for Integrals

Second Fundamental Theorem of Calculus (SFTC)

x

a

df t dt f x

dx

If f(x) is continuous on an interval containing x=a, then

or

u x

a

df t dt f u x u x

dx

4.2

0

1xdt dt

dx

2 1x

Page 7: Mean Value Theorem for Integrals

5.

3

sinx

x

dt dt

dx

3cos cosd

x xdx

2 33 sin sinx x x