POTENTIAL, COEFFICIENTS FOR GROUND RETURN CIRCUITS 371 



(^uently it is important to observe that a coarser kind of approximation 

 may often be good enough. Thus, taking y to be zero, 



Jo u -\- at a 



If g is very small one might use 



Jo 11 + at Ji (1 + 



= llog(l + ?)--J_li(. 

 a \ u) 1 + a 



a)t 



Ordinarily precision is not required in M + IN because \{M + i^V) is a 

 small term in />i2 . 



