How Is the Net Electric Field Calculated at a Point in a Square of Charges?

[littlejon]

Homework Statement

Learning Goal:[/B]
To practice Problem-Solving Strategy 26.1 for point chargeproblems.
Three positively charged particles, with charges q1=q, q2=2q, and q3=q (where q>0), are located at the corners of a square with sides of length d. The charge q2 is located diagonally from the remaining (empty) corner.

Find the magnitude of the resultant electric field E⃗ net in the empty corner of the square.

A.
Determine the magnitude Enet of the net electric field at point P. Use K for the electrostatic constant.
Express your answer in terms of q, d, and K.

Enet =

Homework Equations

kQx/√( x^2+r^2)^3

The Attempt at a Solution

kq/d^2[/B]

 

[haruspex]

The Attempt at a Solution

kq/d^2[/B]

That does not constitute an attempt. I'm sure you can do better.