the.com/taylor series

means A way of rewriting a smooth function as an infinite sum of terms built from its derivatives at a single point, so that nearby values can be approximated using only polynomials.

from Named for Brook Taylor, an 18th-century English mathematician who published the general method in 1715, though the special case centered at zero (later called the Maclaurin series) and related ideas had already been circulating among mathematicians like James Gregory and Isaac Newton. Taylor's name stuck to the general formula largely through later textbooks that formalized and popularized it, not because he was first to glimpse the idea — a common fate for eponymous math terms.