\f20. Evaluate sin (tan '(-9)).In Exercises 5-38, find exact expressions for the 19. tan 25TT 3 TT 12 36. tan 8 indicated quantities, given that 20. tan 17TT 37. tan(- 8 12 TT (2 + v3 21. cos 13TT TI V2 - V2 12 38. tan(- 3TT 8 COS 12 = and sin 2 g = 2 [These values for cos ,, and sin " will be derived Suppose u and v are in the interval ( ", IT), with in Examples 4 and 5 in Section 6.3.] tanu = -2 and tan v = -3. In Exercises 39-66, find exact expressions for the indicated quantities.. Find the lengths of both circular arcs of the unit circle connecting the point ( /2, 1/2) and the endpoint of the radius that makes an angle of 20 with the positive horizontal axis. . Find the lengths of both circular arcs of the unit circle connecting the point ( J2/2, / 2) and the endpoint of the radius the makes an angle of 8 radians with the positive hori- zontal axis. . Find the smallest number :1: such that cos(eI + 1) = 0. . Given that 2 2 sin 225 = 'f 2 nd an exact expression for tan 22.5\". . Suppose you need to nd the height of a tall building. Standing 15 meters away from the base of the building, you aim a laser pointer at the closest part of the top of the building. You measure that the laser pointer is 7 tilted from pointing straight up. The laser pointer is held 2 meters above the ground. How tall is the building