Source: /cirosantilli/multivariate-polynomial

= Multivariate polynomial

A <polynomial> with multiple input arguments, e.g. with two inputs $x$ and $y$:
$$
f(x, y) = x^2 + 2x + y^3 + 1
$$
as opposed to a <polynomial> with a single argument e.g. one with just $x$:
$$
f(x) = x^2 + 2x + 1
$$