20 . When defined, tan (3x) cot (3x) =
(A) −1
(B)
(C) 1
(D) tan^3 3 x
(E) sec^2 3 x − 1
21 . If 4 and 0 are both solutions to the equation q(x) = 0, where q(x) is a polynomial, then it
can be concluded that a factor of q(x) is
(A) x^2
(B) (x − 4)^2
(C) x^2 + 4x
(D) x^2 − 8x
(E) x^2 − 4x
22 . Which of the following could be g(x) if f(x) = 5x^2 + 4 and f(g(3)) = 84?
(A) 3 x − 10
(B) 4 x − 7
(C) 6 x − 17
(D) x^2 − 5
(E) x^2 − 3