WEIBULL(x,alpha,beta,cumulative)
x: number
alpha: scale parameter
beta: scale parameter
cumulative: whether to evaluate the density function or the cumulative distribution function
If the cumulative boolean is true it will return: 1 - exp (-(x/beta)^alpha),otherwise it will return (alpha/beta^alpha) * x^(alpha-1) * exp(-(x/beta^alpha)).
If x < 0 this function returns a #NUM! error. If alpha <= 0 or beta <= 0 this function returns a #NUM! error.
This function is Excel compatible.