ɪn mˈɛni kˈeɪsᵻz, ðə dəmˈeɪn ɪz ɐsˈuːmd təbi ʌnbˈaʊndᵻd ænd ðə ɹˈɛfɹəns pˈɔɪnt ɪz tˈeɪkən tə bˈiː "ɪnfˈɪnᵻɾi", wˌɪtʃ kæn biː mˌeɪd ɹˈɪɡɚɹəs jˈuːzɪŋ lˈɪmɪɾɪŋ tɛknˈiːks.
In many cases, the domain  is assumed to be unbounded and the reference point  is taken to be "infinity", which can be made rigorous using limiting techniques.