Answer:
It is an identity, the proof is in the explanation
Step-by-step 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
