Inverse Chi-squared distribution
This tool calculates the Inverse of Chi-squared Cumulative Distribution Function.
Inverse Chi-squared Distribution formulas
X is a random variable following a exponential distribution of parameter `k > 0` (degrees of freedom).
The inverse of the cumulative distribution function F(x) is also called the 'quantile function', denoted Q(x). We have,
`F(x) = (gamma(k/2,x/2))/(Gamma(k/2))`
where `Gamma(x)` is the gamma function,
and `gamma(x)` is the incomplete gammma function,
`Q(x) = F^(-1)(x)`