Solve this equation when y=0
y=\sqrt{4-x^2}
First of all, to do LaTeX, you need to put your expression between [ math ] and [ /math ] . (Without the spaces!)Originally Posted by bret80
$\displaystyle 0 = \sqrt{4-x^2}$. Square both sides:
$\displaystyle 0 = 4 - x^2$
$\displaystyle x^2 = 4$
$\displaystyle x = \pm 2$
Whenever you square both sides of an equation ALWAYS check to make sure that your solution set satisfies your original equation as squaring occasionally adds extra solutions. In this case, both solutions work.
-Dan