clear
syms A dr w1 r  t;A=3;w1=0.5;r=0.5;dr=1.5;
t=linspace(-5,160,1650);
x=A.*exp(-dr*w1.*t).*sin(sqrt(1-dr^2)*w1.*t+r);
subs(x);plot(t,subs(x));
hold
dec1=A.*exp(-dr*w1.*t);subs(dec1);plot(t,subs(dec1));
dec2=-A.*exp(-dr*w1.*t);subs(dec2);plot(t,subs(dec2));
axisx1=linspace(-12,160,1650);axisy1=linspace(0,0,1650);
axisy2=linspace(-8,5,1650);axisx2=linspace(0,0,1650);
plot(axisx1,axisy1,axisx2,axisy2);