1-21-2 (A)y1=0.10c0s[2n(10t-X)+xzl y2=0.10c0s[27(10t+X)+兀 (SD (B)y=0.10c0s[2(10t-X)-0.25 y2=0.10cos2(10t+X)+0.757]S1 (C)y1=0.10c0s2丌(10t-X)+x y2=0.10c0s2(10t+X)-丌 (SD (D)y1=0.10c0s27(10t-X)+0.757 y2=010c0s2m(10+X)+0.75z](S)(D) (C) (B) 0.10cos[2 (10 ) 0.25 ] y1 =  t − X −  0.10cos[2 (10 ) 0.75 ] y2 =  t + X +  ] 21 0.10cos[2 (10 ) y1 =  t − X +  ] 21 0.10cos[2 (10 ) y2 =  t + X −  0.10cos[2 (10 ) 0.75 ] y1 =  t − X +  0.10cos[2 (10 ) 0.75 ] y2 =  t + X +  (SI) (SI) (SI) (A) ] 21 0.10cos[2 (10 ) y1 =  t − X +  ] 21 0.10cos[2 (10 ) y2 =  t + X +  (SI)