bɪkˈʌz ðə vˈoʊltɪdʒ ˌɔn ɐ tɹænsmˈɪʃən lˈaɪn ɪz ˈɔːlweɪz ðə sˈʌm ʌvðə fˈɔːɹwɚd ænd ɹᵻflˈɛktᵻd wˈeɪvz æt ðæt pˈɔɪnt, ɪf ðɪ ˈɪnsɪdənt wˈeɪv ˈæmplɪtˌuːd ɪz wˈʌn, ænd ðə ɹᵻflˈɛktᵻd wˈeɪv ɪz , ðˈɛn ðɪ ˈæmplɪtˌuːd ʌvðə fˈɔːɹwɚd wˈeɪv mˈʌst biː sˈʌm ʌvðə tˈuː wˈeɪvz ɔːɹ .
Because the voltage on a transmission line is always the sum of the forward and reflected waves at that point, if the incident wave amplitude is 1, and the reflected wave is , then the amplitude of the forward wave must be sum of the two waves  or .