While reading in Signals book, here's what I read:(adsbygoogle = window.adsbygoogle || []).push({});

I=1/2 [(integral sign) cos(n+m)wt dt + (integral sing) cos (n-m)wt dt]

"Because cos wt executes one complete cycle during any interval of duration T, cos (n+m)wt executes (n+m) complete cycles during any interval of duration T. Therefore the first integral in the above equation, which represents the area under n+m complete cycles of a sinusoid, equals zero. The same argument shows that the second integral in the above equation is also zero, except when n=m. Hence I in the above equation is zero for all n is not equal to m."

My question is: How do these integrals become zero?

**Physics Forums - The Fusion of Science and Community**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# How does this integral become zero?

Loading...

Similar Threads - does integral become | Date |
---|---|

B Does integration commute with substitution t=0? | May 16, 2017 |

I Does dP_x dP_y = d^2\vec P : Integration scalar / vector var | Apr 14, 2017 |

A Does the maximum value of the following integral exist? | Oct 17, 2016 |

I How does the limit comparison test for integrability go? | Apr 12, 2016 |

Does this integral exist? | Nov 20, 2015 |

**Physics Forums - The Fusion of Science and Community**