The electric potential of a charge distribution is given by the
equation V(x,y,z) = 3 x2 y2 + y
z3 - 2 z3x, where x, y, z are measured
in meters and V is measured in volts. Calculate the magnitude of
the electric field vector at the position (x,y,z) = (1.0, 1.0,
1.0).