Let \(\theta\) be an angle between \(\pi\) and \(3\pi/2\) such that \(\cos(\theta) = -1/9\). Assume that \(\cos(\theta/2) < 0\). Then if the terminal point of \(\theta/2\) is \((a_1,a_2)\) then what is \((a_1, a_2)\) ?
(a_1, a_2) = (-3/5, 4/5).
