PART 5: DEDUCTION AND APPLICATION: Do not use a calculator when answering Part 5. 5.1 Apply the compound angle expansion cos(x + y)= cosxcosy - sin xsin y to cos 2x and simplify your answer : cos 2x = cos(x + x) . . . . .. (2) 5.2 Complete the square identity: sin x + cos x =...... (1) 5.3 Use the identity in 5.2 and rewrite cos x - sin x in terms of sin x only: . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . .. (2) 5.4 Use the identity in 5.2 and rewrite cos x - sin x in terms of cosx only: . . . . . . . . . . . . . . . . . . . . (2) 5.5 Simplify each expression to a single term: 5.5.1 cos 19 - sin 19 = ........... ( 1 ) 5.5.2 cos2 19 + sin 19 =. . . . ............... 5.5.3 2cos2 50' -1 =........... . . . . 5.5.4 1-2sin250 =...... (1 ) 5.5.5 6cos2 - - 3 =. (2) 5.6. It is given that cos32 =t. Without using a calculator, express cos 16 in terms of t. . . . . . . . . . . . . .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . ... .. .. (4) . . . . . . . . . . . [17] TOTAL: 50 marks