Pre-calculus Final Review Study Guide

csc A cos x (7.3) p. 442. Use sum or difference identities to find the exact value of each trigonometric function. 14.) cos 105 ˚ 17.) sin π/12. Find each exact value if 0 < x < π /2 and 0 < y < π /2. 27.) cos (x – y) if cos x = 3/5 and cos y = 4/5. 28.) tan (x – y) if sin x = 8/17 and cos y = 3/5. Verify that each equation is an identity. ................
................