  Using a property of the q-shifted factorial, an identity for q-binomial
coefficients is proved, which is used to derive the formulas for the q-binomial
coefficient for negative arguments. The result is in agreement with an earlier
paper about the normal binomial coefficient for negative arguments. Some new
q-binomial summation identities are derived, and the formulas for negative
arguments transform some of these summation identities into each other. One
q-binomial summation identity is transformed into a new q-binomial summation
identity.

Combinatorics;Number Theory