Choose the one alternative that best completes the statement or answers the question.
Solve the equation for the indicated variable. (Leave in your answer, when appropriate.)
-$x= \pm \sqrt{r^{2}-y^{2}}$ for $r$
A) $r= \pm \sqrt{x+y}$
B) $r= \pm \sqrt{x^{2}+y^{2}}$
C) $r= \pm \sqrt{x^{2}-y^{2}}$
D) $r=x+y$

Question

Quizplus · Accepted Answer

To solve for $r$, square both sides of the equation to eliminate the square root, resulting in $x^2 = r^2 - y^2$. Then, rearrange the equation to solve for $r^2$, giving $r^2 = x^2 + y^2$. Taking the square root of both sides gives $r = \pm \sqrt{x^2 + y^2}$.

Choose the One Alternative That Best Completes the Statement or Answers