College Algebra / Unit 1 Alg 042 short lesson, about 20 seconds
The Square Root of a Square
Captions available
The idea
For every real number x, the square root of x² is the absolute value of x: √(x²) = |x|.
In practice
√((−4)²) is √16, which is 4 — the distance of −4 from zero, not −4 itself.
Where people slip
The bars guard the principal root when x might be negative.
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.
Something wrong in this lesson? Flag it · Sources for College Algebra