Finding harmonic components with basic arithmetic

[Forcefedglas]

Homework Statement

Homework Equations

I'm guessing trigonometric identities such as sin(a)cos(b) = 1/2(sin(a+b)+sin(a-b)) might be relevant.

The Attempt at a Solution

I've been thinking of some way to get an approximation of each harmonic by working with the Fourier series representation (approximated since it's only sampled for 250ms) of the signal and taking advantage of trigonometric identities but that's about as far as I've gotten, and am having trouble figuring out how I should proceed. Am I in the correct line of thinking so far?

Thanks in advance.

 

[Merlin3189]

I think you could use the principle of Fourier analysis.
If you think of how the Fourier transform is calculated and the hint they gave in sentence 3 of the first paragraph, that should give you a method.

You won't be able to integrate from -∞ to +∞, but from t=o to t= 0.25 should give a decent result at 300Hz

 

[Forcefedglas]

I think you could use the principle of Fourier analysis.
If you think of how the Fourier transform is calculated and the hint they gave in sentence 3 of the first paragraph, that should give you a method.

You won't be able to integrate from -∞ to +∞, but from t=o to t= 0.25 should give a decent result at 300Hz

Thanks, it all makes a lot more sense now. One of the goals was also to minimize the set of sampled sinusoids - I'm guessing I take a N-point DFT and keep reducing N until it's barely within specifications.

EDIT: One more thing though, what's the relevance of point 2 (You may rely on the fundamental frequency component having a larger amplitude than other harmonics)?