Answer :
Answer: 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.
Step-by-step explanation:
Answer:
A relation of two or more numbers
One input one output
there can be more then one input for the same output
just not more then one output for one input