An independent variable is the input or quantity whose value is chosen or changed, while a dependent variable is the output whose value is determined by its relationship to that input. In tables, coordinate graphs, and simple equations such as , the variables are identified by how they relate, not merely by their letters; this distinction supports interpreting patterns and writing equations. Formal experimental design and relationships involving multiple changing variables are beyond this scope.
To identify the variables:
The total cost of a taxi ride is represented by
where is the number of miles traveled and is the total cost in dollars.
Step 1: Find the input.
The number of miles, , can change depending on how far someone rides. So is the independent variable.
Step 2: Find the output.
The total cost, , changes when the number of miles changes. So is the dependent variable.
Step 3: Check the relationship.
If the taxi travels miles, substitute for :
The cost is 14$. The cost depends on the number of miles.
Answer:
Remember: Do not choose based only on the variable’s letter. Ask, “Which quantity is the input, and which quantity depends on it?”
Click a topic below to practice the foundational skills you'll need, learn the steps, or master this skill
Earned ?