Question

I need qestion number d) solution please help me​

Answer 1

It is an identity, the proof is in the explanation

Explanation:

csc(A)-cot(A)=tan(A/2)

I'm going to start with right hand side

tan(A/2)=(1-cos(a))/(sin(a)) half angle identity

tan(A/2)=1/sin(a)-cos(a)/sin(a) separate fraction

tan(A/2)=csc(a)-cot(a) reciprocal and quotient identities