Two point charges, \(+q\) and \(-q\), are fixed on the \(x\)-axis at positions \(x = +\dfrac{d}{2}\) and \(x = -\dfrac{d}{2}\), respectively. A point \(P\) is located on the positive \(x\)-axis at position \(x = r\), where \(r > \dfrac{d}{2}\). What is the exact electric potential at point \(P\) due to the two charges, relative to zero potential at infinity?