If sinx+cosecx =-2 , then valueof Sinⁿx+cosⁿx is (n belongs to N)

Ans is -2^{n plzz explain..}

Hey I dont think the answer is possible 

simple example let n = 2 then sin²x + cos²x which is always equal to one 

How come the answer is -2ⁿ because then it will become 2²= -4 WRONG

Also for first condition sinx comes to be equal to -1 then cosx = 0 cosecx =-1 and similarly other t ratios 

I think the question might be sinⁿx+cosecⁿx = -1ⁿ+ -1ⁿ = 2x(-1)ⁿ