Solution to Line Formation Problem

 We have:

W_u »  N L a _o    ò ^¥₀  f _u  du

But: f _u du= 1/ Öp   [exp (u - u_o)/D u_D ]²  du/D u_D 

if:  (u) »   (u_o)  

Then, effectively:

exp (u -   u_o) =  exp (0) = 1  

Then:

f _u du= 1/ Öp   [1] = 1/ Öp  [D u_D ]²  du/D u_D

= 1/ Öp  [D u_D ] du

W_u »  N L a _o    ò ^¥₀  f _u  du

»  N L a _o    ò ^¥₀  1/ Öp  [D u_D ] du

The curve of growth will then lack the exponential (i.e. increasing slope) characteristic