Separate `[0, (pi)/(2)]` into subintervals in which `f(x) = sin 2x` is (a) increasing (b) decreasing

Separate [0,pi/2] into subintervals in which f(x)=sin3x is increasing or decreasing.

Separate [0,\ pi//2] into subintervals in which f(x)=sin3x is increasing or decreasing.

Separate the intervals [0, (pi)/(2)] into sub intervals in which f(x)= sin^(4)x + cos^(4)x is increasing or decreasing.

Find the intervals in which f(x) = sin 3x, x in [0,pi/2] is (i) increasing, (ii) decreasing.

Find the intervals in which f(x) = sin 3x, x in [0,pi/2] is (i) increasing, (ii) decreasing.

Separate the interval [0,\ pi//2] into sub-intervals in which f(x)=sin^4x+cos^4x is increasing or decreasing.

Separate the interval [0,pi/2] into sub- intervals in which f(x)=s in^(4)x+cos^(4)x is increasing or decreasing.

Find the intervals in which f(x)=sin3x cos3x,0

Find the intervals in which f(x)=s in x(1+cosx), 0

Separate the interval [0,pi/2] into sub intervals in which function f(x)=sin^4(x)+cos^4(x) is strictly increasing or decreasing.