X and Y Intercepts

The y intercept is the point at which the graph of an equation crosses the

y axis.

y

(0,3)

x

y = 2x + 3

The y intercept is the point at which the graph of an equation crosses the

y axis.

y

(0,3)

x

Notice that the x value is zero.

y = 2x + 3

The x intercept is the point at which the graph of an equation crosses the

x axis.

y

(-3/2 ,0)

x

y = 2x + 3

The x intercept is the point at which the graph of an equation crosses the

x axis.

y

(-3/2 ,0)

xNotice that the y value is zero.

y = 2x + 3

Example #1 Find the y and x intercepts. Then graph the line.

y = 2x + 6

Example #1 Find the y and x intercepts. Then graph the line.

y = 2x + 6

y intercepty = 2(0) + 6

y = 6(0,6)

y = 2x + 6

y intercepty = 2(0) + 6

y = 6(0,6)

x intercept0 = 2x + 6

x = -3(-3,0)

Example #1 Find the y and x intercepts. Then graph the line.

Example #1 Find the y and x intercepts. Then graph the line.

y = 2x + 6

(0,6)

(-3,0)

y

x

Example #1 Find the y and x intercepts. Then graph the line.

y = 2x + 6

(0,6)

(-3,0)

y

x

Example #2 Find the y and x intercepts. Then graph the line.

y = 3x + 12

Example #2 Find the y and x intercepts. Then graph the line.

y = 3x + 12

y intercepty = 3(0) + 12

y = 12(0,12)

Example #2 Find the y and x intercepts. Then graph the line.

y = 3x + 12

y intercepty = 3(0) + 12

y = 12(0,12)

x intercept0 = 3x + 12

x = -4(-4,0)

Example #2 Find the y and x intercepts. Then graph the line.

y = 3x + 12

(0,12)

(-4,0)

y

x

Example #2 Find the y and x intercepts. Then graph the line.

y = 3x + 12

(0,12)

(-4,0)

y

x

Practice Time

For each function, find the x and y intercepts. Then graph the line.

1) y = ½ x + 4

1) y = ½ x + 4

y intercepty = ½ (0) + 4

y = 4(0,4)

x intercept0 = ½ x + 4

x = -8(-8,0)

1) y = ½ x + 4

(0,4)

(-8,0)

y

x

2) y = -2 x + 8

2) y = -2 x + 8

y intercepty = -2 (0) + 8

y = 8(0,8)

x intercept0 = -2 x + 8

x = 4(4,0)

2) y = -2 x + 8

(0,8)

(4,0)

y

x

3) y = -3x - 4

3) y = -3x - 4

y intercepty = -3 (0) - 4

y = -4(0,-4)

x intercept0 = -3 x - 4

x = -4/3

(-4/3,0)

3) y = -3x - 4

(0,-4)

(-4/3,0)

y

x

4) y = 8x - 2

4) y = 8x - 2

y intercepty = 8 (0) - 2

y = -2(0,-2)

x intercept0 = 8 x - 2

x = 1/4

(1/4,0)

4) y = 8x - 2

(0,-2)

(1/4,0)

y

x

5) 2x + 3y = 6

5) 2x + 3y = 6

y intercept2(0) + 3y = 6

y = 2(0,2)

x intercept2x + 3(0) = 6

x = 3(3,0)

5) 2x + 3y = 6

(0,2)

(3,0)

y

x

6) 5x + 2y = 10

6) 5x + 2y = 10

y intercept5(0) + 2y = 10

y = 5(0,5)

x intercept5x + 2(0) = 10

x = 2(2,0)

6) 5x + 2y = 10

(0,5)

(2,0)

y

x

7) -3x + 5y = 9

7) -3x + 5y = 9

y intercept-3(0) + 5y = 9

y = 9/5

(0,9/5)

x intercept-3x + 5(0) = 9

x = -3(-3,0)

7) -3x + 5y = 9

(0,9/5)(-3,0)

y

x

8) -2x - 3y = 10

8) -2x - 3y = 10

y intercept-2(0) - 3y = 10

y = -10/3

(0,-10/3)

x intercept-2x - 3(0) = 10

x = -5(-5,0)

8) -2x - 3y = 10

(0,-10/3)

(-5,0)

y