the x-intercepts are where your f(x) = 0
then -x^2 + 2x + 8 = 0
or
x^2 - 2x - 8 = 0
(x-4)(x+2) = 0
x = 4 or x = -2
( I bet your vertex has an x value of 1
How did I find that real easily ? )
Stuck with one more..
f(x)= -x^2 + 2x + 8
I found the vertex, and the axis, but am having trouble putting my x intercepts in order. I know the Y intercept, what is wrong with me? :-)
Homework, eh, I'd rather be hiking..
1 answer