Question

Find the coordinates of the y-intercept and x-intercepts of the following. (image!)

Answer 1

Explanation:

We can do this a couple of ways. We can graph it -- see below. Or we can do the math.

Math

y = x^2 - 2x - 15

This trinomial factors into

y = (x - 5)(x + 3)

from which

x - 5= 0

x = 5

and

x + 3 = 0

x = - 3

The y intercept is the value obtained when all the xs on the right = 0

y = 0^2 - 2*0 - 15

y = - 15

Answer

• x intercepts: (-3,0),(5,0)
• y intercept: (0,-15)

The graph is below.