" (ii) "f(x)=cos^(2)x" is strictly decreasing on "(0,(pi)/(2))

Prove that the function f(x)=cos^(2)x is strictly decreasing in (0,(pi)/(2))

Show that the function f(x) = cos^(2) x is strictly decreasing on (0, (pi)/(2)) .

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

Show that f(x) = cos^(2) x is strictly decreasing on (0, pi//2) .

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

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

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

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