One end of a taut string of length 3 m along the x -axis is fixed at x=0 . The speed of the waves in the string is 100 ms−1 . The other end of the string is vibrating in the y -direction so that stationary waves are set up in the string. The possible waveform (s) of these stationary waves is(are) [Adv. 2014]
a. y(t)=Asin6πxcos350πt
b. y(t)=Asin3πxcos3100πt
c. y(t)=Asin65πxcos3250πt
d. y(t)=Asin25πxcos250πt