a) $\displaystyle f(x) = 1 / sin(x)$ < -- function is differentiable everywhere except 1/2*pi and -1/2*pi...correct??

b) $\displaystyle g(x) = ln(x^2)$...dont know where this one is differentiable

c) $\displaystyle h(x) = f(x) . g(x)$<---- also dont know how to find where this one is differentiable..

please help