What is the root of a number?

The root of a number, often referred to as a square root in the context of mathematics, is defined as a value that, when multiplied by itself, yields the original number. For example, the square root of 9 is 3 because 3 x 3 equals 9. This concept applies not just to whole numbers but also to fractions and decimals.

The other statements do not accurately define or explain the concept of a root. For instance, the notion that a root is always negative is misleading; while every positive number has both a positive and a negative root, the principal square root is defined as the non-negative value. The assertion that a root can have no real solution pertains to negative numbers under square roots when looking for real solutions, but that is a specific scenario rather than a definition of a root itself. Finally, the idea that a root can only be a whole number is incorrect; roots can be rational or irrational, encompassing a wider range of values than just whole numbers. Thus, the correct definition emphasizes the multiplication aspect that leads back to the original number.