Question

Unit step response of the system described by the equation y(n) +y(n-1) =x(n) is:

(a) z^2/(z+1)(z-1)

(b) z/(z+1)(z-1)

(c) z+1/z-1

(d) z(z-1)/z+1

I got this question by my school principal while I was bunking the class.

I want to ask this question from The inverse z-transform and Response of Linear Discrete Systrems in section Digital Control Systems of Control Systems

Answer 1

Right choice is (a) z^2/(z+1)(z-1)

For explanation I would say: Response of the system is calculated by taking the z-transform of the equation and input to the transfer function in the step input.