f(x) = sin x is a strictly decreasing in `(pi/2,pi)`

f(x) = sin x is a strictly increasing in (0, pi/2)

f(x) = cos x is strictly decreasing in (0, pi)

f(x) = cos x is strictly increasing in (pi,2pi)

Show that the function f(x) = (sin3x) is strict decreasing on (0, pi/2)

Prove that the function f given by f(x) = log sin x is strictly increasing on (0,pi/(2)) and strictly decreasing on (pi/(2),pi) .

Prove that the function f(x) = tanx-4x is strictly decreasing on (-pi/3,pi/3)

Prove that the function 'f' given by f (x) = log sin x is strictly increasing on (0,pi/2)

Prove that the function f given by f (x) = log(sin x) is strictly increasing on (0,pi/2) strictly decreasing on (pi/2 , pi)

Prove that the function f given by f (x) = log (cos x) is strictly decreasing on (0,pi/2)

Prove that f(x)="cos"x is strictly decreasing (0,pi)