In Exercises $27-30$ , rectangular coordinates of a point $P$ are given. Use an algebraic method, and approximate exact solution values with a calculator when appropriate, to find all polar coordinates of $P$ that satisfy
$$
(a) \leq \theta \leq 2 \pi \quad(\mathbf{b})-\pi \leq \theta \leq \pi \quad(\text { e }) 0 \leq \theta \leq 4 \pi
$$
$$
P=(-1,-2)
$$