Sparate the interval `[0, pi/2]` into sub-intervals in which `f(x)=sin^(4) x+cos^(4) x` is increasing

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

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

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.

Write the interval in which f(x)=sin x+cos x,x in[0,pi/2] is increasing.

Find the interval(s) in which f(x)= cos(2x+(pi)/(4)), 0 le x le pi is increasing.