\text { 3. (17 points) The point } P=(-2 \sqrt{15}, 4 \sqrt{5}) \text { is on the terminal side of an angle } \theta \text { . } (a) (12

points) Find all trigonometric function values of 0. \text { (b) (5 points) }^{1} \text { Suppose that the angle } \theta \text { is such that } \frac{\pi}{2}<\theta<\pi . \text { Find an angle } \alpha \text { with } \pi<\alpha<\frac{3 \pi}{2} having the same cosine as 0. Your answer should: (i) give an expression of the angle a in terms of explain how you can tell that cos(0) = cos(a). (Using the unit circle can help you in visualizing what a should be.) \text { the angle } \theta ; \text { (ii) explain how you can be sure that } \alpha \text { is such that } \pi<\alpha<\frac{3 \pi}{2} ; \text { (iii) }