//EXAMPLE 2.17.A
clc;
x=[1,1,1,1]
t=-1:0:1;
y(t)=cos(x(t));
disp('the max val of cos function is');
disp(cos(0));
disp('the min val of cos function is');
disp(cos(%pi));
disp('HENCE THE GIVEN SYSTEM IS BOUNDED IN -1 TO 1 HENCE THE GIVEN SYSTEM IS STABLE');