Charges of are located at the two bottom corners of an equilateral triangle with sides of length . A charge of is at that top corner. This arrangement of charge can be considered two dipoles oriented at with respect to one another.
a) Find the electric field (magnitude and direction) at an arbitrary point on the y-axis above/outside the triangle.
b) What are the first two surviving terms in the
binomial-theorem-derived series for the electric field evaluated far from the charges, i.e. - for 2?