The wave functions of two waves traveling in the same direction are given below. The two waves have the same frequency, wavelength, and amplitude, but they differ in their phase constant. Y(x, t) 2 sin(2x - 20nt), and = y(x, t) = 2 sin(2x - 20t + y), where, y is in centimetres, a is in meters, and t is in seconds. The speed of the resultant wave due to the interference between y and y is: a. 80 x cm/s. b. 10 m/s. c. 20 m/s. d. 80 cos(2/2) cm/s. e. 0.1 m/s. f. Other.