Changes

</math>

</math>

where <math>r</math> is the continuously compounded risk-free interest rate, and <math>\sigma</math> is the volatility of the stock. The solution to this differential equation, satisfying the boundary condition

where <math>r</math> is the continuously compounded risk-free [[interest rate]], and <math>\sigma</math> is the volatility of the stock. The solution to this [[differential equation]], satisfying the boundary condition

<math>\Phi(T) = \hbox{max}(S(T)-K,0)</math>

<math>\Phi(T) = \hbox{max}(S(T)-K,0)</math>