The function `y=a(1- cos x)` is maximum when x is-

The function y = a(1-cosx) is maximum when x is equal to

The function y=1-cos x is maximum , when x=

The function y=1-cos x is maximum , when x=...a) 0 b) pi/2 c) pi d) -pi/6

Let y = a(1 - cos theta), x = a(theta- sin theta) , then y regarded as a function of x is maximum when x equals to

The function,f(x)=cos^(-1)(cos x) is

Let y=a(1-cos theta), x = a(theta - sin theta) . Then y regarded as a function of x is maximum when theta equals

The function, f(x) = cos^(-1) (cos x) is

Prove that at x=(pi)/(3), function sin x(1+cos x) is maximum.Also find the maximum value of the function.