Cos2x+sin²x=0.5 ( -3P/2 : 5P/2 )

[latex]1-2sin^2x+sin^2x=0.5\\ -2sin^2x+sin^2x=-0.5\\ -sin^2x=-0.5\\ sin^2x=0.5\\ sin^2x=\frac{1}{2}\\ sinx= +- \frac{\sqrt{2}}{2}\\ x=(-1)^{n+1}\frac{P}{4}+Pn\\ x=(-1)^{n}\frac{P}{4}+Pn [/latex]