Question:

One end of a taut string of length 3m along the x axis is fixed at x=0. The speed of the waves in the string is 100ms⁻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) y(t)=Asin(πx/3)cos(100πt/3), y(t)=Asin(πx/6)cos(50πt/3), y(t)=Asin(5πx/6)cos(250πt/3), y(t)=Asin(5πx/2)cos(250πt)