College Algebra / Unit 4 Alg 218 short lesson, about 20 seconds
The Unchecked-Squaring Error
Captions available
The idea
The unchecked-squaring error reports every root of the squared equation as a solution of the original; the fabricated ones survive only because nobody checked.
In practice
√(2x + 3) = x squares to roots 3 and −1. But √1 = 1, not −1 — the check executes the impostor, and only 3 stands.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
- Nothing. This is a starting point.
Unlocks
- Nothing yet depends on this.
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