Trigonometry question please help

Question

1)Prove that [ cot^2 x ( sec x -1) ] / [1+ sin x] = [sec^2 x ( 1- sin x)] / [1+ sec x] . 

 

2) Show that the function f(x)= ( cos x - sin x) (17 cos x -7 sin x) may be expressed in the form 

    5 cos 2x - 12 sin 2x + k, where k is a constant.

Answer 1

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