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

Prove that the function f(x)=cosx is strictly decreasing in (0,\ pi)

Show that the function f(x) = tan x – 4x is strictly decreasing on [-π/3, π/3]

Prove that the function f(x)=cosx is strictly increasing in (pi,\ 2pi)

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

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

Show that the function f(x)=-3x+12 is strictly decreasing function on R .

Show that the function f(x) = 3 - 2x is strictly decreasing function on R.

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

Prove that the function given by f(x) = cos x is(a) strictly decreasing in (0,pi) (b) strictly increasing in (pi,2pi) , and(c) neither increasing nor decreasing in (0,2pi)

Prove that the function f(x)=cosx is neither increasing nor decreasing in (0,\ 2pi)