Derivation of the Entropy-Area relation for the Extremal Black Hole in Four Dimensions

The relation between entropy and the area of the event horizon of a quantum blackhole in four dimensions is derived. The Reissner-Nordstrom metric for a non-rotating, charged black hole is shown to be modified by the addition of a new $\frac{1}{r^3}$ term arising from the strong interaction. The resulting entropy-area relation agrees with the Bekenstein-Hawking relation.