% question1 %

figure(1)
t=0:0.01:5;
xt=(10*exp(-1*t))-(5*exp(-0.5*t));
plot(t,xt)
xlabel('t VALUES')
ylabel('xt VALUES')
title('xt versus t values')


% question2 %


figure(1)
t=0:0.01:5;
xt=(10*exp(-1*t))+(5*exp(-0.5*t));
plot(t,xt)
xlabel('t VALUES')
ylabel('xt VALUES')
title('xt versus t values')


% question3 %

m=1e-3;
t=-2*m:0.01*m:2*m;

a=0;

for i=1:4


a=a+250;

xt=(20*sin((2*pi*1000.*t)-(pi/3))).*(exp(-1.*a.*t));

subplot(4,1,i)
plot(t,xt)

end

% question4 %

%write this function in m-file and save it as piecex1.m%

function y=piecex1(t)

a=length(t);

for i=1:a

if 1<=t(i) & t(i)<=10
y(i)=10;


else
y(i)=0;

end
end

%write this in command window%

t=-10:0.01:20;

plot(t,piecex1(t))

xlabel('t values')
ylabel('x values')

title('x values versus t values')