Contents
Phasors
$ x(t)=Ae^{j\theta+\phi} $
Where A is the radius of the phasor and $ \phi $ if the offset.
Useful Phasors Facts
$ e^{j\theta} = \cos{\theta}+j\sin{\theta} $
$ Ae^{j[\theta+\phi]}=Ae^{j\theta}e^{j\phi} $
$ \cos{\theta}=\frac{e^{j\theta}+e^{-j\theta}}{2} $
$ \sin{\theta}=\frac{e^{j\theta}-e^{-j\theta}}{2j} $
$ |e^{j\theta}|=1 $
Energy
Discrete
$ E_\infty = \sum_{n=-\infty}^\infty |x[n]|^2 $
Continuous
$ E_\infty = \int_{-\infty}^\infty |x(t)|^2\,dt) $
Power
Discrete
$ P_\infty = \lim_{N \to \infty} (\frac{1}{2N + 1} \sum_{n=-N}^{+N} |x[n]|^2) $
Continuous
$ P_\infty = \lim_{T \to \infty} \left (\frac{1}{2T} \int_{-T}^T |x(t)|^2\,dt \right) $
