1. Find the exact value of cos ( + [) by using trigonometric identities to rewrite and simplify. 2. Verify the identity sin(A - B) sin(A + B) = sin A - sin B. 3. Use trigonometric identities and algebra to find exact solutions tan(x + It) - cos(x + ]) = 0 Give all solutions on the interval [0,2mr]. 4. Given that sin A = 3/7, cos B = -2/5, and that both A and B are in quadrant II, find cos(A - B). Simplify it to a single value, leaving it in the form of a rational number