a function is a rule that assigns each value of the variable to exactly one value of the dependent variable

Let's imagine that we have the following function function:

We have to:

Independent variable: x

Dependent variable: y

For x = -1:

For x = 1:

We observe that the independent variable can only obtain one result.

example 2 – simplify: step 1: completely factor both the numerators and denominators of all fractions. step 2: change the division sign to a multiplication sign and flip (or reciprocate) the fraction after the division sign; essential you need to multiply by the reciprocal. step 3 : cancel or reduce the fractions.