Question

If A, B, C are interior angles of ABC, then show that:
cosec²(B+C)/2) - tan²(A/2)=1​

Answer 1

hope it will help sry for bad hand writing

Answer 2

Answer:

A+B+C=180°

B+C=180°-A

L.H.S.=cosec^2(B+C)/2-tan^2(A/2)

=cosec^2(90°-A/2)-tan^2(A/2)

=sec^2(A/2)-tan^2(A/2).

=1.

L.H.S.=R.H.S-PROVED