31. sin 4 Using Period to Evaluate Sine and Cosine In Exercises 31-36, evaluate the trigonometric function using its period as an aid. 33. cos(7/3) 35. sin(19/6) 37. sin 3) Using the Value of a Function In Exercises 37-42, use the given value to evaluate each function. (a) sin(-1) (b) csc(-1) 39. cos(-1)=- (a) cost (b) sec(-1) 3 QUC Evaluating Sine, Cosine, and Tangent In Exercises 13-22, evaluate (if possible) the sine, cosine, and tangent at the real number. 14. t = 3 T 16. t = 4 4 18. =- 3 5 20. t = 3