For the three polar curves $r_1 = 2 +\operatorname{cos} θ$, $r_2 = 2 + 2\operatorname{cos} θ$, and $r_3 = 2 + 3\operatorname{cos} θ$:

1. What are the minimum values of $r$ for each of the functions? What is the corresponding $θ$-value?

   Hint (a):

   Recall that $–1 ≤\operatorname{cos}(θ) ≤ 1$.

2. How does your answer to part (a) explain what happens to the graphs as $θ$ moves from $\frac { \pi } { 2 }$ to $\frac { 3 \pi } { 2 }$ ?

   Hint (b):