18. A parallel LRC circuit connected across a yariable AC voltage source V= V0 cos(ot) is drawn above. Find: (a) The current I(t) in the primary supply wire (as shown in the figure abeve) with all terms, e.g. the phase o, and the impedance Z defined (the latter in terms of the individual reactances).(b) The average power dissipated by the circuit. Note that (if you are clever and remember what each elements does in the circuit) you don't really have to solve a) to get this answer, although you can certainly get the same answer from a knowledge of V (t) and I(t) and some integration. Hint: To find the answer you must add the currents being drawn by each element separately! Your answer for Z should remind you of parallel addition of resistors, using reactances instead (two of which are n/2 out of phase with the resistor, of course).