Originally Posted by

**Darkhrse99** Sorry for the confusion, the math code is kicking my butt.

I'm trying to find point X on the unit circle.

The book gave me the Y cord of $\displaystyle \frac {-2} {7}$ . I need to find X.

The formula $\displaystyle x^2+ y^2 =1$ is used to find the answer.

I plugged in $\displaystyle x^2 + \frac {-2} {7}squared=1$

Than I get $\displaystyle x^2=1-\frac{4} {49} next I get$ $\displaystyle x^2= \frac{49} {49}- \frac{4}{49}=\frac{45} {49}$ Then you get $\displaystyle x=\sqrt \frac{45} {49}$The answer is suppose to be $\displaystyle x=+ or -\sqrt{5}$.