Figure a is a partial graph of the position function x(t) for a simple harmonic oscillator with an angular frequency of 1.20 rad/s; Figure b is a partial graph of the corresponding velocity function v(t). The vertical axis scales are set by xs = 5.0 cm and vs = 5.0 cm/s. What is the phase constant of the SHM if the position function x(t) is given the form x = xm cos(wt + Φ)?

x (cm) (a) v (cm/s) (b)