close all
clear all 
clc

t = -10:.1:10;
b = 3;
s1 = tanh(t);
s2 = tanh(t-b);
s3 = tanh(t+b);
figure
plot(t,s1,t,s2,t,s3)
grid on
xlabel('time [s]')
ylabel('signal')
title('tanh and its shifted versions')

% printing figure in png format
set(gcf,'PaperUnits','inches','PaperPosition',[0 0 4 3])
print -dpng exercise1.png -r100