Electrostatics

Three charges each of value \(+q\) are placed at the corners of an isosceles triangle \(\mathrm{ABC}\) of sides \(\mathrm{AB}\) and \(\mathrm{AC}\) each equal to \(2 \mathrm{a}\). The mid points of \(A B\) and \(A C\) are \(D\) and \(E\) respectively. The work done in taking a charge \(Q\) from \(D\) to \(E\) is ( \(\varepsilon_0=\) permittivity of free space)