TeXipedia

Chi

Represents the uppercase Greek letter used in mathematics, statistics, and scientific notation.

Overview

Commonly employed across multiple scientific disciplines, particularly in statistical analysis and mathematical formulations.

  • Frequently appears in chi-square distributions and statistical tests
  • Used in particle physics to denote certain quantum states
  • Serves as a variable in mathematical proofs and theoretical physics equations
  • Often encountered in academic papers and scientific literature where Greek notation is standard

Examples

Using the capital Chi in a statistical distribution formula

X∼X(k)X \sim \Chi(k) 
X \sim \Chi(k)

Representing the Chi distribution in a probability density function

f(x;k)=xk−1e−x/22k/2Γ(k/2),x>0f(x; k) = \frac{x^{k-1}e^{-x/2}}{2^{k/2}\Gamma(k/2)}, \quad x > 0 
f(x; k) = \frac{x^{k-1}e^{-x/2}}{2^{k/2}\Gamma(k/2)}, \quad x > 0

Showing the relationship between Chi and Chi-squared distributions

If Z∼X(k), then Z2∼χ2(k)\text{If } Z \sim \Chi(k), \text{ then } Z^2 \sim \chi^2(k) 
\text{If } Z \sim \Chi(k), \text{ then } Z^2 \sim \chi^2(k)