First, f(x) is a periodic function of 2pi, so we know from the properties of the periodic function that 1 and the second derivative of f(x) are all functions with a period of 2pi, and f(2pi)=f(0)=0.

Find f' (x) = 2 (sinx-1) cosxf (x)+(sinx-1) 2f' (x), where x=2pi, where F'(2pi)=f'(2pi), and then x=4pi.

The second problem is that you can't type symbols when eee is IbTheron and nnn is Ita.

F'(eee)=[f(b)-f(a)]/(b-a) If a function x 2 is constructed from Lagrange theorem, then f(x) and x 2 are derived from Cauchy theorem, and f' (nnn)/2nnnn = [f (b)-f (a).