The next three problems refer to two point charges A and B on the x-y plane. With coordinates measured in meters, A is at (-1,0) and carries charge -5nC. B is at (2,0) and carries +4nC.
1. Find the x-component of the electric field Ex at the points (0,0), (-4,0) and (1,0) and plot Ex as a function of x.
2. Find the x-coordinate of the point on the x-axis where the electric field is zero.
3. Find the magnitude of the electric field at the point (2,3).