# Thread: x and y intercepts

1. ## x and y intercepts

Can someone help me find x intercept for

f(x) = 1 - 3(-x-2)2
(the last 2 means square, not sure how to do upper case here)

I have been stuck with this one for couple of hours.

Thanks everyone. This is my first post I am glad I found some on-line help.

2. Hello,

Originally Posted by zdenka
Can someone help me find x intercept for

f(x) = 1 - 3(-x-2)2
(the last 2 means square, not sure how to do upper case here)

I have been stuck with this one for couple of hours.

Thanks everyone. This is my first post I am glad I found some on-line help.
An y intercept is a point where x=0.

$\displaystyle f(0)=1-3(-0-2)^2=1-3(-2)^2=1-3 \cdot 4=-11$
So the point $\displaystyle (0~,~-11)$ is an y intercept.

An x intercept is a point where y=0.

$\displaystyle 1-3(-x-2)^2=0$

$\displaystyle -3(-(x+2))^2=-1$

$\displaystyle (x+2)^2=\frac 13$

$\displaystyle \implies x+2=\pm \frac{1}{\sqrt{3}}$

3. thank you that looks great. I got stuck on the last line!!!