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

Find the intervals in which the function f given by f(x)=sin x-cos x, 0 lt x lt 2 pi is strictly increasing or strictly decreasing.

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

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

Find the intervals in which the function f given by f(x)=sinx+cosx ,\ \ 0lt=x\ lt=2pi is strictly increasing or strictly decreasing.

Find the intervals in which the function f given by f(x)=sinx+cosx, 0lexle2pi is strictly increasing or strictly decreasing.

Find the intervals in which the function 'f' given by: f(x) = sin x-cosx , 0 le x le 2pi is strictly increasing or decreasing.

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