4. Consider a string extending from x=0 to x=L as shown in the figure. The string is anchored at x=0 to a ring of negligible mass which is free to slide on a friction-free rod. At x=L the string is anchored to rigid support. Calculate by use of the appropriate boundary conditions the expression for the waveform y(x, t) and the nth mode and angular frequencies and wavelength. Additionally, sketch the corresponding standing wave patterns for the three lowest modes. L