11. Sketch the graph of y= -2 +3 cos 05/(0-100). 12. Find the fourth term of (3x - 2,2). 13. Develop the identity for cos x cos y'. 14. A triangle has a 25 angle. A side adjacent to this angle is 10 units long and the side opposite this angle is 5 units long. Draw the triangle(s) and find the lengths of the missing side(s) and angle(s). 15. Solve sin 2x = sin x given that 0 < x < 2. 16. Show: 1-3 sin x - 4 sin X cos x = 17. Expand as the sum of individual logarithms, each of whose argument is linear: log 18. (a) Find the sum of the first 10 terms of the geometric series whose first term is -6 and whose common ratio is -2. (b) Find the sum of the first 10 terms of the arithmetic series whose first term is -6 and whose common difference is -2. 1-4 sin x 1 sin x 19. The onlookers gazed in excitement as the number of gremlins decreased exponentially. When they were first observed, there were 48, but in only 50 minutes they had decreased to 42. How long would it take before the gremlins decreased to 25?