Question

Solve : 6sin^2(x)+2sin^2(2x)=5

Answer 1

\[6\sin^2x+2\sin^2(2x)=5\]is the problem?

Answer 2

Yes.

Answer 3

\[6\sin^2(x)+2\sin^2(2x)=5\]\[3(1-\cos(2x))+(1-\cos(4x))=5\]\[3\cos(2x)+\cos(4x)+1=0\]\[3\cos(2x)+(2\cos^2(2x)-1)+1=0\]\[2\cos^2(2x)+3\cos(2x)=0\]\[\cos (2x)(\cos(2x)+\frac32)=0\]

Answer 4

Thank you!

Answer 5

tricky one!

Answer 6

Indeed .