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| − | <math>{e^{2jt}+e^{-2jt | + | <math>frac{e^{2jt}+e^{-2jt}/2}=2cos2t\!</math> |
Revision as of 15:58, 19 September 2008
$ e^{2jt} $ yields $ te^{-2jt} $ and $ e^{-2jt} $ yields $ te^{2jt} $
and the system is linear
since Euler's formulat states that : $ e^{jx} = \cos x + j\sin x \! $
$ e^{2jt} = \cos 2t + j\sin 2t \! $
and
$ e^{-2jt} = \cos -2t + j\sin -2t \! $ $ = \cos 2t - j\sin 2t \! $
$ frac{e^{2jt}+e^{-2jt}/2}=2cos2t\! $
