The x-intercept of a line is the point (a,0) where the line intersects the x-axis.

x and y Intercepts

(a,0)

The y-intercept of a line is the point (0,b) where the line intersects the y-axis.

(a,0)

(0,b)

Consider some points on the x-axis

(5,0)

(-1,0)

(-4,0)

Notice that every point has a y-value of zero

To find the x-intercepts:

1) set y = 0

2) solve for x

3) write the ordered pair (x,0)

Consider some points on the y-axis

(0,4)

(0,-3)

(0,0)

Notice that every point has a x-value of zero

To find the y-intercepts:

1) set x = 0

2) solve for y

3) write the ordered pair (0,y)

Example 1: Find the x and y intercepts for the graph of:

3 5 15x y

To find the x-intercepts:

1) set y = 0

2) solve for x 3 15x 103 5 5x

3) write the ordered pair (x,0)

5x (5,0)

3 5 15x y

5 15y 3 50 15y

3y

(0, 3)

To find the y-intercepts:

1) set x = 0

2) solve for y

3) write the ordered pair (0,y)

Example 2: Find the x and y intercepts for the graph of:

8 3 7x y

To find the x-intercepts:

1) set y = 0

2) solve for x 8 7x 8 703x

3) write the ordered pair (x,0)

7

8x

7,0

8

8 3 7x y

3 7y 8 30 7y

7

3y

70,

3

To find the y-intercepts:

1) set x = 0

2) solve for y

3) write the ordered pair (0,y)