I need help with the following question about charge density and potential.

2. An electric field is given by E\" = k(2 + yj? + 322) (or, in another notation: I? = k(2,y, 32)), where k is a constant with the appropriate unit. Calculate: (a) the charge density at an arbitrary point (x, y, z) (b) the potential at an arbitrary point (x, y, 2), taking the origin as zero potential