65,67,68

For Exercises 65-70, use the information about a and B given in the figures to find the exact function values. Write the answers as decimals or as square roots of decimals. (1, 0) (1, 0) x (-0.8, y) 65.) a. sin 2a b. cos 2a 66. a. sin 23 b. cos 28 b. cos 18 67.ja. sin- 2 2 3 68. ja. sin b. cos 2 2 69. a. sin (a + 3) b. cos (a + B) 70. a. sin (a - B) b. cos (a - B)