Find the monotone interval of function f (x) = 2 / × + SiNx Is there any wood to be broken?

Find the monotone interval of function f (x) = 2 / × + SiNx Is there any wood to be broken?

y′=1/2+cosx
When 1 / 2 + cosx > 0,
That is 2K π - 2 π / 3