The Taylor polynomial of order for a function
about
is the polynomial
where
is a nonnegative integer and the derivatives through
order
exist at
.
Its polynomial degree is at most
. It agrees with
and its first
derivatives at
.
When
has a Taylor series about
, its Taylor polynomial of order
consists of the first
terms. Unlike the infinite Taylor
series, this polynomial requires only the first
derivatives at
and does not require convergence
of the series to
.
The difference
is the Taylor remainder. For example, the Taylor
polynomial of order 2 for
about 0 is
.