# Help in computing Power of two like sine waves

Discussion in 'Math' started by oddlogic, Jan 26, 2014.

1. ### oddlogic Thread Starter New Member

Jan 26, 2014
1
0
Hi,

I'm taking a signals and systems class this semester and one of the problems that I am currently working on is:

x(t) = sin(2t) - sin(2t-.1)

I know that you can compute the power of this waveform by multiplying the integral of the square of x(t) by 1/T. However, I also know that wave forms of differing frequency usually just add by using the A^2/2 method. Is there a similar formula for this instance? I don't feel like computing the integral for the square of x(t) is actually what we are supposed to glean from this coursework.

Is there a general case where the sine waves have only a phase difference (as above) and the same frequency?

Thank you for any assistance,

2. ### t_n_k AAC Fanatic!

Mar 6, 2009
5,448
784
Well you should at least be able to add the two terms by phasor addition to find the resulting AC function.

3. ### WBahn Moderator

Mar 31, 2012
20,237
5,758
First, are you looking for the power or the average power?