\f\f\f\f9. a) Prove that 1 - 2cos x = sinxcosx (tanx - cotx). b) Use Technology Illustrate the identity by graphing with technology.\f1 - sin x sin 2x 11. Prove that COST 2 sin x12. Prove that CSC X - 1 1 - sin x. 2 CSC X 13. Prove that CSCT tanx + cotx. COST