Hi,
Let me rewrite the equation the way i intend to interpret this:
V(t)=Vdc+Vpk*cos(w*t)
What we have here is a sinusoidal wave with a dc offset Vdc.
In other words, the solution to V(t) includes the sinusoidal part plus the dc offset.
I am not sure what else you may want to know about this however, except maybe
that the frequency F is:
F=w/(2*pi)
so we can rewrite the equation as:
V(t)=Vdc+Vpk*cos(2*pi*F*t)
where
V(t) is the entire solution for the voltage at any point in time t,
Vdc is the dc offset
Vpk is the peak of the sinusoidal part
cos is the trigonometric function cosine
F is the frequency
t is the moment in time we look at the solution, and
pi=the constant 3.14159... and
2 is just another constant.
The period of oscillation is tp=1/F in case you want to know that.