(One intermediate revision by the same user not shown)
Line 16: Line 16:
  
 
== B ==
 
== B ==
 +
 +
<font size="3">Let <math>x(t)=cos(4 \pi t) + sin(6 \pi t)</math> with Fourier series coefficients are as follows:
 +
 +
<math>a_{4} = a_{-4} = \frac{1}{2}</math>
 +
 +
<math>a_{6} = -a_{-6} = \frac{1}{2j}</math>
 +
 +
All other <math>a_{k}</math> values are 0
 +
 +
Then the response of <math>x(t)</math> to the system <math>y(t)</math> based on <math>H(s)</math> and the Fouries series coefficients is:
 +
 +
<math>y(t)=\sum_{k=-\infty}^{\infty}a_{k}H(s)</math>
 +
 +
<math>=\frac{1}{s} + \frac{1}{s} + \frac{1}{sj} - \frac{1}{sj}</math>
 +
 +
<math>=\frac{2}{s}</math>
 +
</font>

Latest revision as of 12:58, 24 September 2008

A

Let $ y(t)=\int_{-\infty}^{\infty}2x(t)dt $

Then $ h(t) =2u(t) $

And $ H(s) = \int_{-\infty}^{\infty}h(t)e^{-st}dt $

$ =\int_{-\infty}^{\infty}2u(t)e^{-st}dt $

$ =\int_{0}^{\infty}2e^{-st}dt $

$ =(\frac{-2}{s}e^{-st})|_{0}^{\infty} $

$ =\frac{2}{s} $

B

Let $ x(t)=cos(4 \pi t) + sin(6 \pi t) $ with Fourier series coefficients are as follows:

$ a_{4} = a_{-4} = \frac{1}{2} $

$ a_{6} = -a_{-6} = \frac{1}{2j} $

All other $ a_{k} $ values are 0

Then the response of $ x(t) $ to the system $ y(t) $ based on $ H(s) $ and the Fouries series coefficients is:

$ y(t)=\sum_{k=-\infty}^{\infty}a_{k}H(s) $

$ =\frac{1}{s} + \frac{1}{s} + \frac{1}{sj} - \frac{1}{sj} $

$ =\frac{2}{s} $

Alumni Liaison

Prof. Math. Ohio State and Associate Dean
Outstanding Alumnus Purdue Math 2008

Jeff McNeal