POPPER for Section 6.2 Question\": Which of the following equations islare true for all values of .r ? I. cos(2x)="cosx II. cos(2.r)=2cos:x-l III. sin(2x)=cos:xsin:x IV. sin(2.r)= 7sin(.r)cos(x) A) l and Ill only H) II and Ill only C) II and IV only 1)) II. III. IV only E) I. II, III. IV F) None of these