Usage of one gamma parameter in Mathcad

[hegel]

I can see that most software uses 2 parameters for the gamma function, while Mathcad uses only one. How do I understand this? Is there any way to make an equivalence?

[Werner_E]

Whats wrong with using the help pages?

PTC Prime Help

You can see that Mathcad and also Prime  support the "normal" Euler Gamma function with one argument as well as the incomplete Gamma function with two arguments.

Here the help from Mathcad