Answer
(a) $\frac{7\pi}{12}$
(b) $\frac{2\pi}{5}$
(c) $-\frac{9\pi}{4}$
(d) $-\frac{7\pi}{4}$
Work Step by Step
$$1 ^o = \frac{\pi}{180} \space rad$$
(a) $$105^o = (105) \frac{\pi}{180} \space rad = \frac{7\pi}{12} \space rad$$
(b) $$72^o = (72) \frac{\pi}{180} \space rad = \frac{2\pi}{5} \space rad$$
(c) $$-405^o = (-405) \frac{\pi}{180} \space rad = -\frac{9\pi}{4} \space rad$$
(d) $$-315^o = (-315) \frac{\pi}{180} \space rad = -\frac{7\pi}{4} \space rad$$
