cotan ^2 x/1 + cosec x identic dengan..... a. 1 - cosec x b. 1 + cosec x c. sec x + 1 d. sec x -1 e. cosec x-1 dengan caranya

............. e. cosec x-1

cotan²x + 1 = cosec²x
cotan²x = cosec²x - 1

cotan²x/(1 + cosec x)
= (cosec²x - 1)/(1 + cosec x)
= (1 + cosec x) (cosec x - 1)/(1 + cosec x)
= cosec x - 1

jawabannya di pilihan E