Question

Please answer the picture above.

8th one

Answer 1

LHS
= sec^2 x - cos^2 x
= 1 + tan^2 x + sin^2 x -1
= tan^2 x + sin^2 x
= RHS

Answer 2

=sec^2A-cos^2A=1+tan^2A-(1-sin^2A)
=1+tan^2A-1+sin^2A=tan^2+sin^2A
Thus prooved