Question

20.
sec A - tan A/
sec A+ tan A
= 1-2 sec A tan A + 2 tan² A​

Answer 1

LHS •secA−tanA/ secA + tanA

=secA+tanA/secA−tanA × secA-tanA/secA−tanA

=sec ^ 2A−2secA tanA+tan^ 2A/ sec^ 2 A - Tan^2A

=1+tan ^ 2A − 2secA tanA+ tan ^ 2 A

=1− 2secA tanA+ 2 tan ^ 2A • RHS (proved)

Thanks