Find the square roots of the complex number $z = 3 + 4i$.

Express the complex number $z = 1 + i\sqrt{3}$ in polar form $r(\cos\theta + i\sin\theta)$ and find its principal argument.

Express the following in the standard form $x + iy$ ($x, y \in \mathbb{R}$): (a) $\frac{3 + 2i}{2 - 5i}$ (b) $(1 + i)^4$ (c) $\frac{i^{4n+3} + i^{4n+1}}{i^{4n+2}}$ for any $n \in \mathbb{Z}$

Find the modulus and principal argument of $z = -1 + i\sqrt{3}$, and express it in polar and exponential forms.