Finding force vector fields for 3 dimensional potential energy fields

[Verdict]

Homework Statement

Find the force vector fields (in terms of x, y, z, and any constants) for each of the following 3-dimensional potential energy fields

Question B:
Assume SI units for force, energy, and lengths x, y, z: What must be the units of each of the constants?

Homework Equations

a) V(x,y,z) = a(xyz) + C
b) V(x,y,z) = αx² + βy² + ɣz² + D
c) V(x,y,z) = b e –( σx +ϑy + ρz)

The Attempt at a Solution

I honestly don't even know where to begin with this. I can't find anything about it in my book, nor does google give me any tips. Could someone describe how to treat such a question?

 

[SammyS]

$\vec{F}(x,y,z)=-\vec{\nabla}V(x,y,z)$