From GeoGebra Manual
- InverseWeibull[ <Shape>, <Scale>, <Probability> ]
- Computes the inverse of cumulative distribution function of Weibull distribution at p, where the Weibull distribution is given by shape parameter k and scale parameter λ. In other words, finds t such that P(X ≤ t) = p, where X is random variable with Weibull distribution. Probability p must be from [0,1].