Why Are Mean and RMS Values Close to 30 in Dynamic Signal Analysis?

[krnhseya]

Homework Statement

comment on nature and meaning of results in terms of analysis of dynamic signals.
(why do i see these results and what should we do to increase the accuracy of these two values)

Homework Equations

y=30+(2cos(6*pi*t))

both mean value and rms value come out to be very close to 30ish. (29~31)

The Attempt at a Solution

i really have no idea...rounding errors?

 

[Delphi51]

mean and rms values have to do with signals that vary with time.
They are different ways to average the signal over time.
They normally give quite different answers. For example, the 120 V on a home plugin would is 120 V RMS but has a mean of zero volts.
If you look up the term "root mean square" in your textbook and/or internet, you should find some examples to build up your experience to the point where you can say something about a signal that has a mean of 29 and and rms of 31.