  The Taylor coefficients c and d of the Pion EM form factor are constrained
using analyticity, knowledge of the phase of the form factor in the time-like
region, 4 m_pi^2 \le t \le \tin and its value at one space-like point, using as
input the (g-2) of the muon. This is achieved using the technique of Lagrange
multipliers, that gives a transparent expression for the corresponding bounds.
We present a detailed study of the sensitivity of the bounds to the choice of
time-like phase and errors present in the space-like data, taken from recent
experiments. We find that our results constrain c stringently. We compare our
results with those in literature and find agreement with the chiral
perturbation theory results for $c$. We obtain d \sim O(10)GeV^{-6} when c is
set to the chiral perturbation theory values.
