(a)[3]
The initial term of an arithmetic progression is $-2222$ and the common difference is $17$. Find the value of the first positive term.
(b)[5]
The first term of a geometric progression is $\sqrt{3}$ and the second term is $2\cos\theta$, where $0 < \theta < \pi$. Find the set of values of $\theta$ for which the progression is convergent.