Question

prove the following
1-tansqA/cot sq A-1=tan sq A

Answer 1

taking L.H.S. side
1-tan sq A /cot sq A -1
1- tan sq A / (1/tan sq A) -1
(1- tan sq A) tan sq A / 1- tan sq A
tan sq A
which is equal to R.H.S

Answer 2

L.H.S.= 1 - tan2A / cot2A - 1

          = 1 - tan2A / 1/tan2A - 1

          = 1 - tan2A / 1 - tan2A / tan2A

          = (1 - tan2A) (tan2A) / 1 - tan2A

          = tan2A

          = R.H.S.

  Hence proved.