Recent content by matlabber

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    Proving the Cosine Sum Identity for a Discrete Interval

    interval -\pi:\pi split into M equal intervals. midpoints are y_K
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    Proving the Cosine Sum Identity for a Discrete Interval

    "Proof Beyond Scope of Course" Homework Statement \frac{1}{M}\sum_{j=1}^{M}\cos(mx_{j})=\begin{cases} 1, & \ m \equiv 0\pmod{M}\\ 0, & \text{else} \end{cases} Homework Equations The Attempt at a Solution is statement truthfully accurate? how to show this?
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    Summing cosines of sines and cosines

    Homework Statement \sum_{t=0}^{n-1}cos2 \pi ft(x_{t}- \mu-Acos2 \pi ft-Bsin2 \pi ft) Homework Equations The Attempt at a Solution I know to set = 0 I just am not knowing what to do with the cos after the sum...how do I take this sum?
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    Solution to Sum of Cosines Homework

    thank you very much!
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    Solution to Sum of Cosines Homework

    is it \frac{1-exp(2 \pi fi)^{t}}{1-exp(2 \pi fi)}
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    Solution to Sum of Cosines Homework

    but do I include exp() when I do geometric series?
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    Solution to Sum of Cosines Homework

    Homework Statement I try to simplify to get rid of sum \sum_{k=0}^{n-1}cos(2 \pi fk) Homework EquationsThe Attempt at a Solution I discover I shall use euler equation to form: \sum_{k=0}^{n-1}\frac{1}{2}(e^{2 \pi fki}+e^{-2 \pi fki}) but how to sum exponentials?
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    How can I get the sum inside the exponential?

    Using Geometric Series I get... \frac{1-e^{2 \pi ifn}}{1-e^{2 \pi if}} =\frac{e^{2 \pi ifn}-1}{e^{2 \pi if}-1} Do I want to split up the pieces in the numerator? or Factor?
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    How can I get the sum inside the exponential?

    Hi, You are correct my mistake.\sum_{t=0}^{n-1}e^{2 \pi ift}=\frac{e^{2 \pi ifn}-1}{e^{2 \pi if}-1}=e^{\pi if(n-1)}\frac{e^{\pi ifn}-e^{-\pi i f n}}{e^{ \pi if}-e^{-\pi if}}\\\\\\\\
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    How can I get the sum inside the exponential?

    Homework Statement Show if true: \sum_{i=1}^{n-1}e^{2 \pi ift}=\frac{e^{2 \pi ifn}-1}{e^{2 \pi if}-1}=e^{\pi if(n-1)}\frac{e^{\pi ifn}-e^{-\pi i f n}}{e^{ \pi if}-e^{-\pi if}}\\\\\\\\ Homework Equations I'm really stuck here, just looking for a suggestion as to what equation to use... Can I...
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    Comparing two dependent? groups

    Hi, I have a mathematics/Matlab question. Suppose I have a speaker that serves as a sound source, and two IDENTICAL microphones to the left and right of this speaker. Suppose that each microphone collects data regarding the sound level of the speaker, and that there are over 3,000 data values...
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