How to shift a vector?

Hello all, I'm having some trouble doing a homework question using MATLAB. I have created a vector that models the unit step function with the built-in heaviside function and need to create two new vectors that are shifted by 1 and 2 seconds. I'm confused on how to do this.

So, what I have right now is u1(t). I need to create u2(t-1) and u3(t-2). I've defined my time interval for t =[-5,5,10] and vector u1 as syms u1.

[Roger Stafford]

Look up circshift and see if that will do what you want.