Question

Question #5a13e

Answer 1

`LHS= (1-sin^4 α)/(cos^2 α+2sin^2 α)`

`=( (1-sin^2alpha)(1+sin^2alpha))/(cos^2 α+sin^2 α+sin^2alpha)`

`=( (cos^2alpha)(cancel(1+sin^2alpha)))/(cancel((1+sin^2alpha)))`

`=cos^2alpha=RHS`

Proved