1. Simplify the expression: (1+ cos a)(1- cosa). Choose the correct answer below. A. 1+2 cos a+ sin a B. sin a C. sina D. cos a NO WORK NO CREDIT! 2. 1 What does equal? cos x+1 cos x-1 OA. 2 cscx 3. C. 2 2 - sin x O B. 1 Choose the correct simplified form of cos (x) tan (-x). A. sin x 4. B. - sin x Write an equivalent expression for cos (2x). Choose the correct answer below. OA. 1 sin (2x) B. sec (2x) 5. 1 C. cot (2x) D. sec (2x) Use identities to simplify cosy D. - sinx OC. tan x D. cos x cot x Which function does CSC X cotx CSC X simplify to? A. cos x B. 1 C. cscx