What is the difference between an expression and a function?

Expressions are “syntactical” objects, i.e. pieces of language. Functions are (mathematical) objects, i.e. pieces of the world. A function is described/specified by an expression; the same function can be described by more than one expression.

Is an expression a function?

Thus an expression represents a function whose inputs are the values assigned to the free variables and whose output is the resulting value of the expression.

What makes an expression a function?

function, in mathematics, an expression, rule, or law that defines a relationship between one variable (the independent variable) and another variable (the dependent variable). Functions are ubiquitous in mathematics and are essential for formulating physical relationships in the sciences.

What makes an expression not a function?

Any input-output chart where an input has two or more different outputs is not a function. For example, if you see the number 6 in two different input spaces, and the output is 3 in one case and 9 in another, the relation is not a function.

What is a difference between an expression and an equation?

You can define a numerical expression as a group of numbers and variables with no equal sign. An equation is a group of numbers and variables that does include an equal sign.

What are examples of expressions?

The definition of an example of expression is a frequently used word or phrase or it is a way to convey your thoughts, feelings or emotions. An example of an expression is the phrase “a penny saved is a penny earned.” An example of an expression is a smile.