I don't understand what this problems means....do I need some more equations? The voltage in a circuit is given in SI units by V = 80sin200t. What is the voltage at t = (1/60) s? A. 0V B. 15V C. 80V D. -15V Can you even have a negative voltage? I guess I just don't understand the complexities of this problem. Also guys....Do you guys know what the equations needed to help find charge and voltage through capacitors in series and parallel??