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Two waves have the same amplitude, speed, frequency moving in the same region of space. The resultant wave can be expressed like the sum of two waves: psy(y,t) = Asin(ky+wt) + Asin(ky-wt+pi).

Express each wave individually using the complex representation. Demonstrate, using this representation, that the resultant wave can be expressed such as: psy(y,t)=2Acos(ky)sin(wt).

What is the amplitude at y=0, y=pi/k?

Attempt to answer:

I've tried breaking this problem into pieces. I'm having quite a bit of difficulty converting the wave equations into complex form.

I started by splitting the equation in two.

psi1(y,t) = (ky + wt)

psi2(y,t) = (ky - wt + pi)

From there, I'm not sure what to do. I know that I have to convert it into a form of Ae^i(wt-kx+epsilon).

Would simply be: psy1(y,t) = Ae^i(wt+ky) and psy2(y,t) = Ae^i(-wt+ky) ?

I'm pretty confused about this. I don't know where to go from here or even if what I did has sense to it. Hopefully someone can help me out!

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# Homework Help: Expressing waves in complex form

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