Key Idea Electric field at a point is equal to the negative gradient of the electrostatic potential at that point. Potential gradient relates with electric field according to the following relation E=dr−dV E=−∂r∂V=[−∂x∂Vi^−∂y∂Vj^−∂x∂Vk^]=[i^(2xy+z3)+j^x2+k^3xz2]