How to graph functions over time with a delay using MATLAB?

I am struggling to graph a function over time with a delay using MATLAB. I have two examples listed below:

• Ex1) x(t) = -10e^-.1t u(t) for which my code looks like:

t = 0:.1:100;

x = -10*exp(-.1*t);

plot(t,x,'linewidth',2)

• Ex2) x(t)=-10e^-.1t u(t-5)

I am not sure how to incorporate the (t-5) into my code. What is the proper procedure to include this parameter in the graph?

Any and all help is appreciated! Thank you!

Answer 1

[Asad (Mehrzad) Khoddam]

You can use:

 -10*exp(-.1*t).*(t>=5);

[Jonathan Hollingsworth]

Thank you sir. That was very helpful.

Answer 2

[Sokna San]

t =0:.1:100;

x =-10*exp(-.1*t);

subplot(2,2,1)

plot(t,x,'linewidth',2)

x1=-10*exp(-.1*t).*heaviside(t-5);

subplot(2,2,2)

plot(t,x1,'linewidth',2)