Question

prove geometrically 1+tan^2 A=sec^2A

Answer 1

So, here is the answer

Answer 2

1 +tan^2A

=1+( Sin^2A/Cos^2A)

=(Cos^2A+Sin^2A) / (Cos^2A)

=1/Cos^2A

=Sec^2A

LHS= RHS proved