Greek Alphabet

Name Upper case Lower case Often used for:
Alpha A $\alpha$  
Beta B $\beta$  
Gamma $\mit\Gamma$ $\gamma$  
Delta $\mit\Delta$ $\delta$ A small number
Epsilon E $\epsilon,\varepsilon$ Another small number
Zeta Z $\zeta$  
Eta H $\eta$  
Theta $\mit\Theta$ $\theta,\vartheta$ Angle
Iota I $\iota$  
Kappa K $\kappa$  
Lambda $\mit\Lambda$ $\lambda$ A linear function
Mu M $\mu$  
Nu N $\nu$  
Xi $\mit\Xi$ $\xi$ Unknown quantity, x
Omicron O o  
Pi $\mit\Pi,\prod_{i=1}^n$ $\pi,\varpi$ Product, $\pi=3.14159\dots$
Rho P $\rho,\varrho$  
Sigma $\mit\Sigma,\sum_{i=1}^n$ $\sigma$ Sum, standard deviation
Tau T $\tau$  
Upsilon $\mit\Upsilon$ $\upsilon$ Rarely, if ever, used
Phi $\mit\Phi$ $\phi,\fie$ Another angle
Chi X $\chi$  
Psi $\mit\Psi$ $\psi$  
Omega $\mit\Omega$ $\omega$ Angular velocity, the end.