Sqrt(3)*cosx - sinx = 2cos5x
sqrt(3)*cosx - sinx = 2cos5x
(sqrt(3)*cosx)/2 - (sinx)/2 = cos5x
cos(pi/6)*cosx-sinx*sin(pi/6)=cos5x
cos(pi/6+x)=cos5x
5x=pi/6+x
4x=pi/6
x=pi/24