515 Appendix A Solutions t o the Exercises h) A(j0) = 7l - c) 7'1ie first zcro of the aperlure furicfion should be at half the saiiiple freqiiency the argument ol Ihe si fiinct,ion should be equal to The first zero of'the si trrrii The ros term has peiiotl U+, IS 7r at = 7r - r, -+ SO= 72 H a term in square hrackcts arc at 24 Hz and 48 Hz Accordingly the zcros of the