(→Power) |
(→Energy) |
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− | <math>E=\frac{1}{2}((u+\frac{1}{2}sin(2(u)))|_{u=-2}^{u=2\pi-2}</math> | + | <math>E=\frac{1}{2}((u+\frac{1}{2}sin(2(u)))|_{u=-2}^{u=2\pi-2} + C</math> |
− | <math>E=\frac{1}{2}(2\pi -2 + .0744 -(-2 - 0.0349)</math> | + | <math>E=\frac{1}{2}(2\pi -2 + .0744 -(-2 - 0.0349)) +C </math> |
− | <math>E= | + | <math>E=\pi</math> |
− | + | ||
== Power == | == Power == |
Revision as of 05:12, 5 September 2008
cos(t-2)
not finished
Energy
u = (t-2)
$ E=\int_0^{2\pi}{|cos(u)|^2dt} $
$ E=\frac{1}{2}\int_0^{2\pi}(1+cos(2(u)))dt $
$ E=\frac{1}{2}((u+\frac{1}{2}sin(2(u)))|_{u=-2}^{u=2\pi-2} + C $
$ E=\frac{1}{2}(2\pi -2 + .0744 -(-2 - 0.0349)) +C $
$ E=\pi $
Power
$ E=\frac{1}{2\pi-0}\int_0^{2\pi}{|cos((t-2))|^2dt} $
$ =\frac{1}{2\pi-0} *{\frac{1}{2}}\int_0^{2\pi}(1+cos(2(t-2)))dt $
$ =\frac{1}{4\pi}((t-2)+\frac{1}{2}sin(2(t-2)))|_{t=0}^{t=2\pi} $
$ =\frac{1}{4\pi}(2\pi+0-0-0) $
$ =\frac{1}{3} $