The function f ( x ) = ( x 2 − 1 ) − 1 {\displaystyle f(x)=(x^{2}-1)^{-1}} defined for all real x except for −1 and 1 is unbounded. As x approaches −1 or 1, the values of this function get larger and larger in magnitude. This function can be made bounded if one considers its domain to be, for example, [2, ∞) or (−∞, −2].