\magnification=\magstep2

$$
   \Delta P = {{C} \over {d} }   
         \qquad \qquad 
   \Delta P = {{C} \over {d^2} }   
$$

$$
   \Delta P = {{C} \over {d^N} }   
$$


$$
   \log (\Delta P)  \quad = \quad \log ( {{C} \over {d^N} } )  \quad
               =  \quad \log(C)  - N \log(d) 
$$



\bye
