Vinculum (symbol)
From Simple English Wikipedia, the free encyclopedia
A vinculum is a horizontal line placed over a mathematical expression. It shows that this expression belongs together as a group. (Vinculum is Latin for "chain".)
Examples of its use include the case of a group of infinitely repeating digits, for example,
It is also used in common arithmetic to show that the numerator is being divided by the denominator as a whole group.
It is also used in the notation of a radical to indicate the radicand whose root is being indicated. In the next case, the quantity ab + 2 is the radicand, and thus has a vinculum over it.
![\sqrt[n]{ab+2}](../../../math/8/0/8/8080f31cf28dcb85bfe46f8386cd7202.png)
It is also used to show the repeating terms in a periodic continued fraction. Quadratic irrational numbers are the only numbers that have these.
