Given a vector field V(x,y,z) = (xi + yj + zk)/(r^3) where r = sqrt(x^2 + y^2 + z^2)

a) what is the x,y,z components of V(x,y,z)

b) partial derivatives of each component

do i substitute the r^3 with the sqrt thing or i just leave it as r^3 when i find the x,y,z components and derivatives?