Question

Question #66d08

Answer 1

`LHS=(1-tan^2 x+tan^4 x)`

`=((1-tan^2 x+tan^4 x)(1+tan^2x))/(1+tan^2x)`

`=((1^2-1xxtan^2 x+(tan^2 x)^2)(1+tan^2x))/(1+tan^2x)`

`=(1^3+(tan^2x)^3)/sec^2x`

`=cos^2x(1+tan^6x)=RHS`