I need help with this equation

Question

What is the y-intercept of the graph of the parabola whoose equation is y=x²-2x-8?

Answer 1

Geraldine:

Plug x=0 into y=x²-2x-8

Answer 2

To find the y-intercept, simply plug in 0 as your x to see where it crosses the y-intercept.

y=0^2-2(0)-8

y=0+0-8

y= -8

So the y-intercept is (0,-8) - you can use this to find other y-intercepts by remembering it will be (0,c).

Answer 3

The y-intercept occurs when x = 0. Set x equal to 0 and solve for the corresponding y-value.

y = x² - 2x - 8

y = 0² - 2(0) - 8 = 8

The function will cross the y-axis at the point (0,8).