how to plot negative frequency in x axis ?

how to plot an impulse response ?

Answer 1

[Sam Chak]

@Belal Ahmed

This impulse response can plotted by following the example here:

https://www.mathworks.com/help/control/ref/lti.impulse.html

a = [0 1; -1 -1];
b = [0; 1];
c = [1 0];
sys = ss(a, b, c, 0);
impulse(sys)