0,25-cos([latex] \frac{ \pi }{2} [/latex]+x)=sin[latex] \frac{x}{2} [/latex]*cos[latex] \frac{x}{2} [/latex]

0.25 - cos(p/2 + x) = sin(x/2)*cos(x/2) 0.25 +sin(x) = sin(x)/2 0.25 + sin(x) - sin(x)/2 = 0 sin(x)/2 = 0.25 sin(x) = -1/2 x = (-1)^(n+1) * p/6 + p*n