Advance functions (4U) 5to 7 full answers with full steps and explanation handwriting only please.

6. Solve. In the interval [0, 2n ] a. 2cosx - 1 = 0 b. 5cosx - V3 = 3cosx [K/U 2, 2] c. sin x - 3sin xcosx = 0 d. 3sin x+ 3cos2x =2 [A 3, 3] 7. Prove the following identities: [T a. 2 Cosa _ secx cos 2x + 1 b. 1- tan"X - cos 2x 1 + tan x C. sinx + sinxcot'x = cscx 5. If sinA = = and cos B = -, where A is acute angle and B is obtuse angle. Find the exact value of: cos(A+B)