1. Find the 5th roots of 1 + 2i.
2. Find the real and imaginary parts of f (z) = cos(z).
3. Determine all the values of z ∈ C (if any) at which the given function is differentiable.
(a) f(z) =|z|2.
(b) g(z) = xy + 2yi where z = x + iy.
4. Show that
f(z) = Re(z)Im(z) + iIm(z)
is differentiable at only one point in C, and find this point.
5. Consider the function I : C → C defined by
f(z) = ex= cos(y) + iex sin(y),
where z = x + iy. Show that f is differentiable at all points of C and calculate its derivative.
6. Let u(x, y) = 4xy3 - 4x3y.
Show that there exists a real-valued function v(x, y) so that
f(z) = u(x, y) + iv(x, y)
is differentiable at all points z ∈ C.