lines
DESCRIPTION
Lines. y. 6. 4. 2. x. O. –6. –4. –2. 2. 4. 6. y. y. y. y. y. –2. 6. 6. 6. 6. 6. –4. 4. 4. 4. 4. 4. –6. 2. 2. 2. 2. 2. x. x. x. x. x. O. O. O. O. O. –6. –6. –6. –6. –6. –4. –4. –4. –4. –4. –2. –2. –2. –2. –2. 2. 2. 2. 2. 2. 4. 4. 4. - PowerPoint PPT PresentationTRANSCRIPT
Lines y
xO 2 4 6
2
4
6
–6
–4
–2–6 –4 –2
How do you graph the line and find its equation when
1. You are given the y-intercept and the slope.
Example: y-intercept is 1 and slope is 2/3. Equation:
2. You are given a point and the slope.
Example: point is (–2, 3) and slope is –3. Equation:
3. You are given two points.
Example: 1st point is (3, –4) and 2nd point is (2, 1). Equation:
Slope-Intercept Form:
where m is the slope and b is the y-intercept
Example:
y = x – 3
Point-Slope Form:
where (x1, y1) is the point and m is the slope
Example:
y – 1 = 2(x – 2)
General Form:
Example:
4x – 3y = 12
Two-Intercepts Form:
where a is the x-intercept and b is the y-intercept
Example:
y
xO 2 4 6
2
4
6
–6
–4
–2–6 –4 –2
y
xO 2 4 6
2
4
6
–6
–4
–2–6 –4 –2
y
xO 2 4 6
2
4
6
–6
–4
–2–6 –4 –2
y
xO 2 4 6
2
4
6
–6
–4
–2–6 –4 –2
3
21
23
yx
// Lines and Lines:
1st: Sketch y = ¾x + 1
2nd: Sketch the line parallel to it, and have y-intercept = –2.Q: What is the slope?
Q: What is the equation?
3rd: Sketch the line perpendicularto it and have y-intercept = 4.Q: What is the slope?
Q: What is the equation?
y
xO 2 4 6
2
4
6
–6
–4
–2–6 –4 –2