A] Use method 1 from the middle of page 180 to divide (8/15) by (4/9). B] Use method 2 from the middle of page 180 to divide (8/15) by (4/9). C] Use a calculator to divide (8/15) by (4/9). D] Let B=-B in the "cosine of a sum" identity to derive the "cosine of a difference" identity E] Use ID # 4's pair of IDs to simplify each of the following to a single trig expression: E1) cos (90 + 0) E2) cos (90 - 0) E3) cos (n + 0) E4) cos (It - 0) F] Use ID # 4's pair of IDs to simplify each of the following to a real number: F1) cos 82 cos 98 - sin 82 sin 98 F2) cos (5n/12) cos (n/4) + sin (5n/12) sin (n/4) G] Answers to exercises in E & F above: -sin 0 sin 0 -cos 0 -cos 0 -1 sqrt(3)/2