The cdf of geometric distribution is given by $ F(x)=1-(1-p)^x$.

I want to calculate the inverse of it, for example, $F^{-1}(U)$

I am doing the following

f(x_) := 1 – (1 – p)^x;

InverseFunction(f(u))

But I do not get anything.

my ultimate goal is to generate sample of a random variable that has geometric distribution.