Show that, the function `f(x)=cos 2x` is increasing at `x=(3pi)/4`.

Show that the function f(x) =sin^(4)x+cos^(4)x is increasing in (pi)/(4) lt x lt (3pi)/(8) .

Show that the function f(x)=sin(2x+pi//4) is decreasing on (3pi//8,\ 5pi//8) .

Show that the function f(x)=sin(2x+pi/4) is decreasing on (3 pi/8,5 pi/8)

show that the function f(x)=sin x is strictly increasing in (0,(pi)/(2)) strictly decreasing in ((pi)/(2),pi)

Show that the function given by f(x) = sinx is increasing in (0,pi/2) .

Show that the function f(x)= |sinx + cos x| is continuous at x= pi

Is the function f(x) = cos x strictly increasing in (0, pi) ?

The function f(x)=sin^4x+cos^4x increasing if :

Show that the function f(x)=cot^(-1)(sin x+cos x) is decreasing on (0,pi/4) and increasing on (pi/4,pi/2)