3.) Find the ordinary derivatives of the following functions or explain why the derivative does not exist (a) f(x) = rcosha, TER, (b) f(z) = 2, zEC, (c) g(z) = zZ, z EC. Hint: You will need to use the definition of the derivative in terms of the limit in some cases. You can write the limit > > 0 for z e C as lime-+0 ce, where e, O E R