The Inverse Operation

A root reverses a power. The square root of 49 asks: what number times itself gives 49? Answer: 7. The cube root of 27 asks: what number cubed gives 27? Answer: 3. Roots undo exponentiation the way subtraction undoes addition.

The radical sign comes from the Latin word "radix," meaning root, like the root of a plant. Square roots are the most common, but cube roots, fourth roots, and beyond all follow the same logic: find the base that was raised to a power. Babylonian scribes were already computing accurate square roots around 1800 BC, long before calculators existed.