Find the area A[x_] of the largest rectangle that can be inscribed in a semicircle of radius r = 3 ft. Let x be the angle formed by the line from the center of the semicircle through one corner of the rectangle. Also find the domain.

I’m sure you could google it. my profile picture might

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.