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Next we compute the coefficients.  Since we are using sin and cos, we can use their equivalent formulas.
 
Next we compute the coefficients.  Since we are using sin and cos, we can use their equivalent formulas.
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 +
<math>x(t) = (5+3j)cos(4t) + (1+2j)sin(3t)</math>
 +
<math> = (5+3j)(\frac{e^{4jt} +e^{-4jt}}{2}) + (1+2j)(\frac{e^{j3t} + e^{-j3t}}{2j})</math>

Revision as of 14:01, 23 September 2008

The Formulas for Fourier Series

$ x(t) = \sum^{\infty}_{k = -\infty} a_k e^{jk\pi t}\, $

where $ a_k=\frac{1}{T} \int_0^Tx(t)e^{-jk\omega_ot}dt $

Chosen Formula

$ x(t) = (5+3j)cos(4t) + (1+2j)sin(3t) $

Computation

First we want to compute the period (T) for this function. The period of sin and cos is 2pi, therefore the combined period is also 2pi.

Next we compute the coefficients. Since we are using sin and cos, we can use their equivalent formulas.

$ x(t) = (5+3j)cos(4t) + (1+2j)sin(3t) $ $ = (5+3j)(\frac{e^{4jt} +e^{-4jt}}{2}) + (1+2j)(\frac{e^{j3t} + e^{-j3t}}{2j}) $

Alumni Liaison

Basic linear algebra uncovers and clarifies very important geometry and algebra.

Dr. Paul Garrett