How do you use and find the y-intercept?
Kayla Boylan,
7th grade student

Hi Kalya,

The y-intercept of a graph is the y-coordinate of the point where the graph crosses the y-axis.

In the diagram the point where the graph crosses the y-axis is P. Since P is on the y-axis its coordinates are (0,b) for some number b. b is the y-intercept.

To find the y-intercept substitute x = 0 in the equation and solve for y. For example if you have the graph of

y = 6 x2 + 2 x + 8
then substitute x = 0 to get
y = 0 + 0 + 8 = 8
and thus y = 8 is the y-intercept.

Cheers,
Penny 		 

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