  Using a large sample of D0 to K mu nu and pi mu nu decays collected by the
FOCUS photoproduction experiment at Fermilab, we present new measurements of
the q^2 dependence for the f+(q^2) form factor. These measured f+(q^2) form
factors are fit to common parameterizations such as the pole dominance form and
compared to recent unquenched Lattice QCD calculations. We find m_pole =
1.93+-0.05+-0.03 GeV/c^2 for D0 to K mu nu and m_pole = 1.91+0.30-0.15+-0.07
GeV/c^2 for D0 to pi mu nu and f-^{K}(0)/f+^{K}(0) = -1.7+1.5-1.4+-0.3.
