Determine the magnitude of the electric field at the point

Question

Use the following to answer questions 1-2:

The electric potential V(x, y, z) in a region of space is given by

V(x, y, z) = 125(2x² + 2y² - 5z²)

1. Determine the magnitude of the electric field at the point (0.200 m, 0.300 m, 0.100m).

2. What is the radius of the equipotential contour corresponding to V=375 V and z=1?