How a square or sawtooth wave can have a certain frequency?

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A square or sawtooth wave is composed of an infinite series of sine waves with varying frequencies and amplitudes, but they exhibit a well-defined frequency or period in their plots. The frequency of these waves is primarily determined by the fundamental harmonic in the Fourier series. While ideal square and sawtooth waves can be mathematically represented as sums of sine waves, real-world versions do not perfectly match this idealization. The concept of frequency in these waves typically refers to the fundamental frequency, which is the lowest harmonic present. Understanding this relationship is crucial for accurately analyzing and calculating the frequency of such waves.
MrMuscle
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Hello!

I know that a square or saw tooth wave consists of infinite amount of sinousoids each having different frequency and amplitude. But when I look at their plot they seem to have a well defined frequency or period. Which term in the Fourier series determines their frequency? Does a saw tooth or square wave have an uncertainty in its frequency? How can I calculate the frequency of such a wave?

Thanks for all the answers in advance!
 
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You've got this somewhat backwards. The square or sawtooth wave is something we generate in the real world. It has amplitude, frequency, and so forth. The Fourier analysis gives us a mathematical way to analyze it. The map is not the territory.

An IDEAL square wave, for example, is in fact the same as its Fourier analysis says it is ... a sum of an infinite sequence of sine waves. No ACTUAL square wave is like that but we can pretend they are for the purpose of analysis.
 
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What is called the frequency or period is usually that of the fundamental (lowest) harmonic.
 
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