How do you simplify 1-4sin^2xcos^2x14sin2xcos2x?

1 Answer

It can be simplified to cos^2(2x)cos2(2x) or 1/2(cos4x+1)12(cos4x+1)

Explanation:

We have that

1-4sin^2x*cos^2x=(1^2-(2cosx*sinx)^2)=(1-(sin2x)^2)=cos^2(2x)14sin2xcos2x=(12(2cosxsinx)2)=(1(sin2x)2)=cos2(2x)

Also we know that

cos(4x)=2*cos^2(2x)-1=>cos^2(2x)=1/2(cos4x+1)cos(4x)=2cos2(2x)1cos2(2x)=12(cos4x+1)

Remarks

It is known that : sin^2(2x)+cos^2(2x)=1sin2(2x)+cos2(2x)=1