  We study the asymptotic expansion of the 6j-symbol using the Schulten-Gordon
recursion relations. We focus on the particular case of the isosceles
tetrahedron and we provide explicit formulas for up to the third order
corrections beyond the leading order. Moreover, in the framework of spinfoam
models for 3d quantum gravity, we show how these recursion relations can be
used to derive Ward-Takahashi-like identities between the expectation values of
graviton-like spinfoam correlations.
