Thanks for the reply.
I am able to prove that the equation is correct if both the amplitudes that interfere are equal by using A2 = p0 + Cos(0,5*δ).
But they do not have to be equal i assume, and therefor I am kinda lost on how to come up with an expression for the resultant amplitude that...
Yes, I did try. Yes, I have opened my textbook( Physics for scientists and engineers, Tipler & Mosca). But I did not find anything that helped me. So I've been sitting here, trying to get something usefull out of playing around with formulas that i don't have think will work.
This I did not...
Homework Statement
To waves with the same frequency interfere. The intensity of the two waves are I1 and I2. Show that the resultant intensity is:
I = I1 +I2 + 2*sqrt(I1*I2)*cos(δ)
Where δ is the phase difference between the two waves.
Hint: Use the relation between intensity and...