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==Energy==
 
==Energy==
 
<math>E_\infty = \int_{-\infty}^\infty |x(t)|^2dt</math>
 
<math>E_\infty = \int_{-\infty}^\infty |x(t)|^2dt</math>
 +
 +
<math>= \int_{-\infty}^\infty |e^{jt}|^2dt</math>
 +
 +
<math>= \int_{-\infty}^\infty |cos(t) + jsin(t)|^2dt</math>      (Euler's Formula)
 +
 +
<math>= \int_{-\infty}^\infty {\sqrt{cos^2(t) + sin^2(t)}}^2dt</math>      (Magnitude of a Complex Number)
 +
 +
<math>= \int_{-\infty}^\infty dt</math>
 +
 +
<math>= t|_{-\infty}^\infty</math>
 +
 +
<math>= \infty - (-\infty)</math>
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 +
<math>= \infty</math>
 +
 +
==Power==
 +
<math>P_\infty = \lim_{T \to \infty} \frac{1}{2T} \int_{-T}^T |x(t)|^2dt</math>
 +
 +
<math>= \lim_{T \to \infty} \frac{1}{2T} \int_{-T}^T |e^{jt}|^2dt</math>
 +
 +
<math>= \lim_{T \to \infty} \frac{1}{2T} \int_{-T}^T |cos(t) + jsin(t)|^2dt</math>      (Euler's Formula)
 +
 +
<math>= \lim_{T \to \infty} \frac{1}{2T} \int_{-T}^T {\sqrt{cos^2(t) + sin^2(t)}}^2dt</math>      (Magnitude of a Complex Number)
 +
 +
<math>= \lim_{T \to \infty} \frac{1}{2T} \int_{-T}^T dt</math>
 +
 +
<math>= \lim_{T \to \infty} \frac{1}{2T} t|_{-T}^T</math>
 +
 +
<math>= \lim_{T \to \infty} \frac{1}{2T} [T - (-T)]</math>
 +
 +
<math>= \lim_{T \to \infty} \frac{1}{2T} (2T)</math>
 +
 +
<math>= \lim_{T \to \infty} 1</math>
 +
 +
<font size = "5">
 +
<math>= 1</math>

Latest revision as of 22:14, 4 September 2008

Signal

$ x(t) = e^{jt} $

Energy

$ E_\infty = \int_{-\infty}^\infty |x(t)|^2dt $

$ = \int_{-\infty}^\infty |e^{jt}|^2dt $

$ = \int_{-\infty}^\infty |cos(t) + jsin(t)|^2dt $ (Euler's Formula)

$ = \int_{-\infty}^\infty {\sqrt{cos^2(t) + sin^2(t)}}^2dt $ (Magnitude of a Complex Number)

$ = \int_{-\infty}^\infty dt $

$ = t|_{-\infty}^\infty $

$ = \infty - (-\infty) $

$ = \infty $

Power

$ P_\infty = \lim_{T \to \infty} \frac{1}{2T} \int_{-T}^T |x(t)|^2dt $

$ = \lim_{T \to \infty} \frac{1}{2T} \int_{-T}^T |e^{jt}|^2dt $

$ = \lim_{T \to \infty} \frac{1}{2T} \int_{-T}^T |cos(t) + jsin(t)|^2dt $ (Euler's Formula)

$ = \lim_{T \to \infty} \frac{1}{2T} \int_{-T}^T {\sqrt{cos^2(t) + sin^2(t)}}^2dt $ (Magnitude of a Complex Number)

$ = \lim_{T \to \infty} \frac{1}{2T} \int_{-T}^T dt $

$ = \lim_{T \to \infty} \frac{1}{2T} t|_{-T}^T $

$ = \lim_{T \to \infty} \frac{1}{2T} [T - (-T)] $

$ = \lim_{T \to \infty} \frac{1}{2T} (2T) $

$ = \lim_{T \to \infty} 1 $

$ = 1 $

Alumni Liaison

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

Jeff McNeal