9. Which expression is equivalent to: sin B.7 cos4.4 + cosB.7sin 4.4 A. sin 38.28 B. cos4.3 C. sin13.1 D. sin 4.3 10. Which of the following can be written as sin 7x ? A. cos 5x - sin 2.r B. sin 3xcos 2.r - cos 3xsin 2x C. cos S.r + sin 2x D. sin Sroos 2x + cos S.rsin 2.r 10. 11. 1 -2sin - is equivalent to: A. 2 cos- B. sin 12 C. Cos D. cos- 12 11. 12. Write the following as a single trigonometric function: 4cos42 sin 42 A. 2sin 42 B. 2cos 42 C. 2sin 84 D. 4cos 21 12