Question

1+tan4a.tan2a= sec4a

Answer 1

sec^ 4a_tan^4a

(sec^2a)^2-(tan^2a)^2

(sec ^2a+tan^2a(sec^2a_tan^2a)

(a^2_b^2)=(a+b) a_b)

(sec^A+tan^2a).1

(1+tan^2a+tan^2a)

(1+2 tan^2a)