Which of the following is not always true for a function?
a.
each x-value has only one y-value.
b.
the range is the y-values.
c.
each y-value has only one x-value.
d.
the domain is the x-values.

in mathematics, a function is a relationship between two variables such that the value of one of the variables, called the dependent variable, is determined by the value of the other variable, called the independent variable. there is a specific term we use to describe the set of independent variables of a function.