Use the trigonometric substitution to select the algebraic e

Use the trigonometric substitution to select the algebraic expression as a trigonometric function of where--

Solution

5 sqrt 5 = sqrt ( 625 - 25x^2 )

x = 5 cos theta

5 sqrt 5 = sqrt ( 625 - 25 * 25 cos^2 theta )

5 sqrt 5 = sqrt ( 625 sin^2 theta )

5 sqrt 5 = 25 sin theta

sqrt 5 = 5 sin theta

sin theta = sqrt 5 / 5

cos theta = sqrt 5 / 5

option b is correct