9.4.21  Inverse distribution functions: icdf

The icdf command finds the inverse cumulative distribution function for a probability distribution.

• cdf takes one or more mandatory arguments and one optional argument.
  • distd, the name of the function that finds the distribution’s density function.
  • parameters, any parameters that would normally be passed to distd.
  • x, a number.
• icdf(distd,parameters) returns an expression for the inverse cumulative distribution function for distd with parameters parameters.
• icdf(distd,parameters,x) returns the value of the inverse cumulative distribution function at x. parameters.

Example.
Input:

Output: