What does radicand mean?
A radicand is the quantity appearing under a radical sign in a mathematical expression. In the expression √25, for example, 25 is the radicand and 5 is its square root. The term is most familiar from elementary algebra, but it applies to any indexed root, including cube roots and roots of algebraic expressions. When finding real square roots, the radicand cannot be negative because no real number has a negative square. In more advanced mathematics, the radicand may itself be a fraction, polynomial, variable expression, or other algebraic quantity, and its structure can determine how the root is simplified. The word is more precise than saying that a number is “under the square root,” since it names the mathematical role of that quantity. It comes from Latin and ultimately shares its root with words such as radical and radius.
nounIn an algebraic expression, the quantity that appears beneath a radical sign and whose value is sought when taking a root. For example, in √7, the number 7 is the radicand.
- The quantity or algebraic expression beneath a radical sign, especially the number whose square root, cube root, or other root is being taken.
"When simplifying the expression, the mathematician first identified the radicand."
"The radicand must be nonnegative if the result is to be a real number."
"In √(x + 4), the expression x + 4 is the radicand."
The plural is used when referring to the quantities or expressions beneath more than one radical sign.
"Both radicands are nonnegative."
Every number hiding under a radical sign has a name: it is the radicand.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does radicand come from?
The word derives from Latin radicandus, a gerundive meaning “to be rooted” or “that is to be rooted,” formed from radix, “root.” It entered English in the 18th century as a mathematical term for the quantity placed under a radical sign.
How radicand is actually used
This is primarily a formal term used in mathematics and technical writing. It is especially common in elementary algebra, where the radicand of a square root is usually a number or simple expression.
Easily confused with radicand
A radicand is the quantity beneath a radical sign, whereas a radical is the symbol itself or an expression involving roots.