Which of the following function is decreasing on \(\left(0,\frac{\pi}{2}\right)\)?1\(\sin(2x)\)2\(\tan(x)\)3\(\cos(x)\)4\(\cos(3x)\)Answer & explanation+Correct answer: option 3\(f(x)=\cos x\) then \(f^{\prime}(x)=-\sin x0\) in \(\left(0,\frac{\pi}{2}\right)\)
