  The slow-roll field equations for the case of non-minimally coupled scalar
fields are obtained in two ways: first using the direct generalization of
slow-roll conditions in the minimal coupling case to non-minimal one; and,
second, conformal transforming the slow-roll field equations in the Einstein
frame to the Jordan frame and then applying the generalized slow-roll
conditions. We compare the difference of two methods in calculation of the
spectral index, $n_s$, for a model example. The second method seems to be more
precise.
