Example 1 Easy
If f(x) = 2x + 7, what is f(4)?
- 8
- 11
- 15
- 22
Show answer and explanation
Answer: 15
Substitute 4 for x: f(4) = 2(4) + 7 = 15.
SAT Math skill page
SAT Function Notation Practice
Read f(x) as a rule: plug in the input carefully, then answer what the output means.
10-16 min practice time 3 examples on page Advanced Math
What this tests
What to know for this SAT skill
- Evaluate f(x) for a given input
- Interpret function notation in word problems
- Find an input when the output is given
- Compare values from tables, graphs, and equations
Practice examples
Try a few SAT-style questions
Example 2 Medium
If g(x) = x^2 - 3 and g(a) = 13, which could be the value of a?
- -4
- -3
- 3
- 13
Show answer and explanation
Answer: -4
Solve a^2 - 3 = 13, so a^2 = 16. The possible values are 4 and -4.
Example 3 Hard
A function h gives the total cost, in dollars, of buying n tickets. What does h(6) = 84 mean?
- Six tickets cost $84.
- Eighty-four tickets cost $6.
- Each ticket costs $84.
- The function has 6 outputs.
Show answer and explanation
Answer: Six tickets cost $84.
The input is the number of tickets and the output is total cost, so h(6) = 84 means 6 tickets cost $84.
Quick drills
Practice this skill from more angles
Evaluate f(x) for a given input
Pause before the answer choices, write the rule or setup you need, then check whether the question is asking for the value, the relationship, or the best-supported conclusion.
Interpret function notation in word problems
Pause before the answer choices, write the rule or setup you need, then check whether the question is asking for the value, the relationship, or the best-supported conclusion.
Find an input when the output is given
Pause before the answer choices, write the rule or setup you need, then check whether the question is asking for the value, the relationship, or the best-supported conclusion.
Compare values from tables, graphs, and equations
Pause before the answer choices, write the rule or setup you need, then check whether the question is asking for the value, the relationship, or the best-supported conclusion.
Avoid these traps
Common mistakes on this skill
Solving before naming the task
The SAT often hides the real skill inside familiar wording. Identify the rule, relationship, or question type first.
Choosing an answer that only partly fits
Many wrong answers are close. Check every condition in the question before committing.
Skipping the final check
Reread what the question asks for so you do not answer a nearby but different question.
Study plan
How to practice this skill in Dolphin
- Read the question and name the tested skill before looking at the choices.
- Write the equation, rule, or passage relationship in plain language.
- Eliminate answers that violate the setup or overstate the evidence.
- Review misses by writing the exact trap that pulled you toward the wrong answer.
Related practice
Build the surrounding skills
Skill cluster
Keep practicing SAT Math
FAQ
Questions about SAT Function Notation Practice
What is the best way to practice SAT Function Notation Practice?
Start with a few focused examples, review the mistake pattern, then mix the skill into full SAT practice so you can recognize it in context.
Why does this skill matter on the SAT?
It shows up in short, high-leverage questions where one missed rule or setup can quickly cost a point.
Can Dolphin SAT help me drill this skill?
Yes. Dolphin SAT can surface targeted practice, track missed questions, and help you review the patterns that keep repeating.