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The Square Root of a Square

This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.

State

For every real number x, the square root of x² is the absolute value of x: √(x²) = |x|.

Show

√((−4)²) is √16, which is 4 — the distance of −4 from zero, not −4 itself.

Watch for

The bars guard the principal root when x might be negative.

Builds on

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Unlocks

  • Nothing yet depends on this.