hello all
i have a question about forier theorem
According to the Forier theorem, any practical periodic functon of frequency ω° can be expressed as an "infinite" sum of sine or cosine functions that are integral multiples of ω° ---------------why
To understand the full concept behind the fourier series draw the following steps what i say, Consider a square wave of 1Hz, over it draw a sine wave with 1Hz freq, and again draw a sine wave with 3Hz freq, and again draw a sine wave with 5Hz freq. Now you can see that the sum of the three sine wave can built a square wave(approximatelly. If the sine wave you drawn for 1Hz(fundamental),3Hz(3rd hormonics),5Hz(5th hormonic-the even hormonics are absent in this case) is extended for infinite you can exactly construct a 1Hz square. I hope you understand why you need to take an infinite sine terms for a fourier series.
This is a simple example for your understanding purpose
It doesn't go much into the Gibbs phenomenon, which results from truncating the series prior to infinity, but that's also available as a separate link (at the bottom).