Root

Root, quantities that when taken a designated number of times will result in a specific quantity. Some roots are the second (square) or third (cube) time a number is designated; for example, the square of 25 is 5, because the root 5 is designated twice: 5 × 5 = 25. Similarly the cube of 27 is 3, because the root 3 is designated three times: 3 × 3 × 3 = 27. The number of times a root is designated is called its index. In algebra, the number that may stand for x and satisfy the equation is also called a root.

See also: Algebra; Factor.