I can see at least two ways to do it; we can probably find others as well.
(%i1) omega (x, y, z) := x * y * z^2 $
(%i2) p : [2, 3, -1] $
(%i3) V : [1, 2, 3] $
(%i4) p2 : p + t * V $
(%i5) deltaomega : apply (omega, p2) - apply (omega, p);
2
(%o5) (t + 2) (2 t + 3) (3 t - 1) - 6
... and then the rest is the same. Or define omega
so its argument is a list:
(%i1) omega (p) := p[1] * p[2] * p[3]^2 $
(%i2) p : [2, 3, -1] $
(%i3) V : [1, 2, 3] $
(%i4) p2 : p + t * V $
(%i5) deltaomega : omega (p2) - omega (p);
2
(%o5) (t + 2) (2 t + 3) (3 t - 1) - 6
Notice that in both cases I've defined omega
as a function.