i've seen in some texts they use sin(pi t)/pi t = sinc(t) and in some they've used just sin(t)/t = sinc(t) each gives different answer for example if i want to find FT of rect(t/tow) using former one gives sinc(w tow/2 pi) and if i use former one i get sinc (w tow / 2) so how to know which one to use ?? Thnx. . . .