ACT Preparation / Unit 10 ACT 0910 short lesson, about 20 seconds
Piecewise Functions
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The idea
A piecewise function uses different formulas on different parts of its domain. To evaluate it, first find which piece's interval holds the input.
In practice
f(x) = x + 2 for x < 0, and x² for x ≥ 0: f(−3) = −1, and f(3) = 9.
Where people slip
Watch the boundary: at x = 0 here, the second rule applies, because of the ≥ sign.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
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