The interval in which the function `f(x)=sin x+cos x` in `x in [0, 2pi]` is

Find the intervals in which the function f(x) = sin x +cos x,x in [0, 2pi] is (i) strictly increasing, (ii) strictly decreasing.

Find interval (s) in which the function f(x) = sin x + cos x, x in (0, pi//2) is increaing or decreasing.

Find the intervals in which the function f(x) = sin^(4) x + cos^(4) x AA x in [0, pi//2] is increasing and decreasing.

Find the interval where the function f(x) = sin x + cos x, x in [0, 2pi] is increasing.

Find the intervals in which the function f(x)=sin x-cos x where 0 lt x lt 2pi is decreasing.

Find the intervals in which the function f(x)=sin x-cos x where 0 lt x lt 2pi is increasing.

Find the intervals in which the function given by f(x)=sin x+cos x, 0le x le 2pi is strictly increasing.