2. (5 points) Find the exact values of the following expressions. Beware: just writing the value that your calculator gives you if you input the expressions below will net you

no marks. \text { (a) }(1 \text { point }) \sin \left(\cos ^{-1}\left(\frac{3}{4}\right)\right) \text { . } \text { (b) }(2 \text { points }) \tan \left(\arcsin \left(-\frac{2}{5}\right)\right) \text { (c) (2 points) } \cos \left(\arctan \left(-\frac{\sqrt{13}}{6}\right)\right) \text { . }