Question

prove the identity sec^2A-tan^2A=1

Answer 1

1+tan^2=sec^2.


hope it will help you

Answer 2

= sec^2 A-tan^2 A=1

Since sec A = 1/cos A and

tan A = sin A/ cos A


=) 1/cos^2 A - sin^2 A/cos^2 A = 1

=) (1-sin^2 A) / cos^2 A = 1

Since sin^2 A + cos^2 A = 1

=) cos^2 A = 1- sin^2 A

=) cos^2 A / cos^2 A = 1

=) 1 = 1

Lhs = Rhs..

Hope it's helpful to u.