Precalculus help please?

Make the indicated trigonometric substitution in the given algebraic expression and simplify.
Square root of 9-x^2
X=3sin(theta)

fcas802014-10-17T15:21:49Z

Favorite Answer

9-(3sin(theta))^2
9 - 9 sin^2(theta)
9(1- sin^2(theta))
9cos^2(theta)