What is the first backward difference of y(n)?
(a) [y(n)+y(n-1)]/T
(b) [y(n)+y(n+1)]/T
(c) [y(n)-y(n+1)]/T
(d) [y(n)-y(n-1)]/T
I had been asked this question in homework.
My doubt is from Backward Difference Method in portion Digital Filters Design of Digital Signal Processing