The voltage applied to a circuit is 100√2 cos (100πt)

The voltage applied to a circuit is 100√2 cos (100πt) volts and the circuit draws a current of 10√2 sin (100πt + π/4) amperes. Taking the voltage as the reference phasor, the phasor representation of the current in amperes is

V(t) = 100√2 cos (100πt)

i(t) = 102		100πt +	π	+	π	-	π
			4		2		2

= 102 cos		100πt -	π
			4

I =	102	∠ -	π
	2		4

= 10 ∠ -	π	.........(i)
	4