Final answer:
A function with 1 term is called a monomial, which is a single-term algebraic expression and may include constants and variables. Options like binomial, trinomial, and polynomial represent expressions with two, three, or many terms respectively.
Step-by-step explanation:
If a function has 1 term, it is called a monomial. A monomial is an algebraic expression with only one term. It can be a constant, a variable, or the product of constants and variables. In contrast to monomials, polynomials are algebraic expressions with one or more terms, which can include monomials, binomials (with two terms), or trinomials (with three terms). For example, in a mathematical function like quadratic equations which are a type of second-order polynomial, there are typically three terms and they are known as trinomials.