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Period of a sum of cosine signals

  • Thread starter Quincy
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  • #1
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Homework Statement


Find the period of the signal x(t) = 2 + 4cos(40Pi*t) + 3cos(60Pi*t) + 4cos(120Pi*t).


Homework Equations





The Attempt at a Solution



The fundamental frequency (fo) = 10 Hz, since that's the greatest common factor of all the frequencies of the cosine signals. So the period would be 1/10 = 0.1 s. But my professor took points off for it, why?
 

Answers and Replies

  • #2
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how many times per sec does each component of the signal by itself repeat?

How much time does each component of the signal take to go through one cycle?
 

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