The gamma function has two forms. One with a single parameter z, the other with two parameters, z and x.
You're using the second form.
Success!
Luc
thumbsup. How can I ever thank you enough lucmeekes, i really aooreciate it.
Built-in function "Gamma([a], z)" - "returns either Euler's gamma function of z, or the incomplete gamma function of z with degree a. To type G, press G+[Ctrl]+G".