Electric field at point p if p is on a bisector between two opposite charges

[zyphriss2]

Homework Statement

Determine magnitude of the electric field at the point P. The two charges are separated by a distance of 2a. Point P is on the perpendicular bisector of the line joining the charges, a distance x from the midpoint between them. Express your answer in terms of Q, x, a, and k.

Homework Equations

e=(kq)/(r^2)

The Attempt at a Solution

Top e=((8.99x10^9)*Q)/(tan^-1(a/x))
Bottom e=((8.99x10^9)*Q)/(tan^-1(a/x))

I just don't know how to determine the magnitude, and express my answer in terms of the given variables...i do know that the answer is in terms of q

 

[tiny-tim]

Hi zyphriss2!

The Attempt at a Solution

Top e=((8.99x10^9)*Q)/(tan^-1(a/x))
Bottom e=((8.99x10^9)*Q)/(tan^-1(a/x))

oooh … why so trigonmetric?

just use Pythagoras! ​