358 



THEORY OF HEAT. 



[CHAP. IX. 



or 



or 



VTT 



denoting by r the quantity q A/ 

 must be taken by hypothesis from 





or from 



from 



-oo to 



2 



I jf+ 



&amp;gt; / XI- 6 



VCD 



The two last limits may, from the nature of the function e~ r&amp;lt;i , be 

 replaced by these: 



~HU . x 



r Kt 

 CD 



r 



, and r = oo . 



It follows from this that the value of u is expressed thus : 



/ffi PU r Q IHL iTLt r 



u = e * KS e CDS dre&quot; e~ w ^ e ona idre-^j 

 the first integral must be taken from 



+ ,^- to r = oo , 



r = 



and the second from 



x 



to r = co . 



