Some General Purpose Formulas and Definitions
General Purpose Formulas | |
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Series | |
Finite Geometric Series Formula | $ \sum_{k=0}^n x^k = \left\{ \begin{array}{ll} \frac{1-x^{n+1}}{1-x}&, \text{ if } x\neq 1\\ n+1 &, \text{ else}\end{array}\right. $ |
Infinite Geometric Series Formula | $ \sum_{k=0}^n x^k = \left\{ \begin{array}{ll} \frac{1}{1-x}&, \text{ if } |x|\leq 1\\ \text{diverges} &, \text{ else }\end{array}\right. $ |
Euler's Formula and Related Equalities | |
Euler's formula | $ e^{jw_0t}=cosw_0t+jsinw_0t $ |
Cosine function in terms of complex exponentials | $ cos\theta=\frac{e^{j\theta}+e^{-j\theta}}{2} $ |
Sine function in terms of complex exponential_ECE301Fall2008mboutin | $ sin\theta=\frac{e^{j\theta}-e^{-j\theta}}{2j} $ |
Definition of some Basic Functions (what engineers call "Signals") | |
sinc function_ECE301Fall2008mboutin | $ sinc(\theta)=\frac{sin(\pi\theta)}{\pi\theta} $ |