Question

Solve the following equation: cos^2(2x)-sin^2(2x)=0

Answer 1

Hello,

since
`cos^2{a}-sin^2{a}=cos(2a)`

cos^2(2x)-sin^2(2x)=0
==>cos(4x)=0
==>4x=π/2+kπ
==>
`x= (\pi)/(8) + (k\pi)/(4)`