MathAdvanced MathLow frequency
SAT Math: Piecewise Functions
12+ practice questions in Praczo
What you need to know
The concept, explained
- 1
A piecewise function has different rules (equations) depending on where the x-value falls.
- 2
When evaluating f(x) for a specific number, FIRST determine which domain condition that number satisfies.
- 3
THEN, plug the number ONLY into the equation corresponding to that condition. Ignore the other equations.
- 4
A solid dot on a graph means the value is included (≤ or ≥). An open dot means it is excluded (< or >).
Common mistakes
- ✗ Plugging the x-value into all equations and adding the results together.
- ✗ Using the equation for x < 0 when evaluating the function exactly at x = 0.
Try a sample question
SAT-style practice
Let f(x) = { 2x + 1 if x < 3 ; x² if x ≥ 3 }. What is the value of f(3)?
12+ questions ready to practice
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