The Total solution for NCERT class 6-12
Solve:
4 sin-1x = Π - cos-1x
4sin-1x+cos-1x=Π
3sin-1x+sin-1x+cos-1x=Π
3sin-1x=Π/2 [sin-1x+cos-1x=Π/2]
sin-1x=Π/6
x = sinΠ/6=0.5