Dadas as funções:
f(x) = sen(x) + \frac{1}{2} . cotg(x), g(x) = \frac{sec(x)}{1+sec(x)} e h(x) = xe^{x} . cosec(x).
Analise as afirmativas seguintes.
I. f'(x) = cos(x) - \frac{1}{2} . cosec^{2}(x)
II. g'(x) = \frac{sec(x)tg(x)}{(1+sec(x))^{2}}
III. h'(x) = e^{x} . cosec(x)(-x . cotg(x) + x + 1)