f( x )=cos3x−15cosx+8  in  [ π/ 3 , 3π/ 2 ] is increasing or decresing

Find the intervals in which the function f given by f(x)=sinx-cosx,0lexle2π is strictly increasing or strictly decreasing.

If f(x) = sin x - cos2x, find f'(π/6) .

∫0^(π/2) (sinx−cosx) dx

find the interval in which f(x)=cos(2x+π/4) is strictly increasing.

Express tan^-1(cos x/ 1 - sin x ), − 3π/ 2 < x < π/ 2 in the simplest form.

f(x)=cos^(2)x+cos^(2)(pi/3+x)-cosx*cos(x+pi/3) is

f(x)=cos^(2)x+cos^(2)(pi/3+x)-cosx*cos(x+pi/3) is

f(x)=cos^(2)x+cos^(2)(pi/3+x)-cosx*cos(x+pi/3) is

secx=2 and x belongs to ( −π/3,π/3) what are the values of x.