1.1) a) Show that the function u(x, t) = A sin[2x(x/2 -vt)] represents a wave moving toward the right (increasing x) by drawing on the same axes the curve at t=0 and t = t/8, one eighth of its period. (Spreadsheet optional. Hint: It is useful to plot u/A vs x/2: that gives a general result without having to worry about specific values for A or 2.) b) What would the equation u(x,t) for a wave moving to the left be