6. The voltage of the power supply of an AC-DC coupled circuit is given by the function of V(t) = 120 sin(4t - 12). where t is time, in seconds, and V(1) is the voltage, in volts, at time t. a) Find the maximum and minimum voltages and all times that they occur. [T -3] b) Determine the voltage at a time of 10 s, and by how much is it changing? [T - 1]