How to Find Intercepts From an Equation

Finding Intercepts
  • x Intercept is where the graph of an equation crosses the x-axis
  • y Intercept is where the graph of an equation crosses the y-axis

How To find the intercepts

What InterceptSteps
x intercepts (x, 0)1. Set y=02. Solve for x
y intercepts (0, y)1. Set x=02. Solve for y

Example

Find the intercepts of y = x2 − 9

x intercept

set y=0

0 = x2 − 9

x2 = 9

x = 3 or −3

The x intercepts of y = x2 − 9 are (3,0) and (−3,0)

y intercept

set x=0

y = 02 − 9

y = −9

The y intercepts of y = x2 − 9 is (0,-9)

And here is the graph of x2 – 9 to confirm what we found:

Finding Intercepts Example

Learn More

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