SOLUTION: For questions 1 through 3, let sin(a) = 4/5 cos(b) = -8/17 1. Find sin(a + b) 2. Find cos(2a) 3. Find cos(b/2) given pi/2 < b < pi 4.Find sin(tan^-1(x) + sin^-1 (3/5))

Algebra ->  Trigonometry-basics -> SOLUTION: For questions 1 through 3, let sin(a) = 4/5 cos(b) = -8/17 1. Find sin(a + b) 2. Find cos(2a) 3. Find cos(b/2) given pi/2 < b < pi 4.Find sin(tan^-1(x) + sin^-1 (3/5))      Log On