**1. The problem statement, all variables and given/known data**

On the x axis, charge +Q lies at x = -a and charge -Q lies at x = +a. Point P lies on the axis at

x = +b, where b > a.

**a)**Work out the electric field magnitude of P

**b)**What is the direction of this field?

**2. Relevant equations**

E=kqr/r3

**3. The attempt at a solution**

E=2kQa/(b2-a2) + 2kQa/(b2-a2)=

Ep=**4kQab/(b^2 – a^2)^2**. My teacher said that the solution was correct, however my work was not.

For b, I determined the direction to be to the right towards the negative charge.

I would appreciate any assistance.

http://ift.tt/1ekJw9a