However, a function y=g(x) that is strictly monotonic, has an inverse function such that x=h(y) because there is guaranteed to always be a one-to-one mapping from range to domain of the function. Also, a function can be said to be strictly monotonic on a range of values, and thus have an inverse on that range of value. For example, if y=g(x) is strictly monotonic on the range then it has an inverse x=h(y) on the range [g(a), g(b), but we cannot say the entire range of the function has an inverse.