say i have the following waveforms

V1=10cos(wt)
V2=20sin(wt)

and i am told to find an analytic expression for the resulting voltage waveform

fristly i found the V1+V2 add the two phasors at t= 0 to get 22.4 and then i found theta which is 26.5 (tan^-1(10/20)) but now im confused will the expression be:

V=22.4sin(wt+26.5)

or

V=22.4cos(wt+26.5)

mathman