. Determine the exact value of each trigonometric ratio. Rationalize all ratios. \text { d) } \cos \left(\frac{25 \pi}{6}\right) \text { b) } \tan \left(60^{\circ}\right) \text { c) } \cos \left(-\frac{5 \pi}{4}\right) \text { d) } \cot \left(-120^{\circ}\right)