A wave has the equation y = 4 sin(3t-6x) (SI units). a. Is the wave traveling in the +x or -x direction? b. What are the: amplitude, period, wavelength, wave vector, frequency and angular frequency (all with units)? c. Sketch a graph of this wave at t = 0.900 s.. d. Sketch a graph of the displacement vs. time at a position x = 0.400m