Question

prove that( cotA -1) / 2 -sec^2A = cotA /1+tanA

Answer 1

LHS=cotA−1

2−sec2A

=1tanA−1

2−(1+tan2A)

=1−tanA

tanA

1−tan2A

=1-tanA

tanA(1−tan2A)

=1-tanA

tanA(1−tanA)(1+tanA)

=1

tanA(1+tanA)

=cotA

1+tanA