Question

(1 + tanA - secA) (1 + tanA + secA) = ?​

Answer 1

Step-by-step explanation:

multiply the terms

(1+tanA+secA)+ (tanA+tan^2A+tanAsecA)- (secA+secAtanA+sec^2A)

On cancellation we get

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

we know that sec^2A - tan^2A=1

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

=1+ 2tanA-1

=2tanA