APPLICABLE TO MATHEMATICS, &C. 365 



+ 



(p,-p+^p.-AP3y "^ (R-p+/,p,-feP3) 



(P.-Pa)'^ (P.-Ps) 



P P 



(P^-P-}-/,P-^p7y + (r-p+ap.-apT) 

 (P.-Ps/ (P.-P3) 



or (p,_p+;,p,_A P3) +^'> p,-P4-^V-feP3 + ^^ 

 P.-P3 P.-P3 



nr P(Pi-P3) . P.(P.-P3) -(P,-P3) 



"^ P,-P+/lP,-AP3^P2-P+AP-/iP3 



P P^ -1 



®' F,--p+KP,-hF,^ V,-F+hF-hF, 



orP>P.-P2+P-^P+/»P3 



or hP > ;iP3 



or P > P3 



Therefore, if P be greater than P3, we shall 

 have the attractive force of A on B greater than 

 the repulsive force of A on B, for all values of x 



greater than p'p • 



And, if P3 be greater than P, we shall have 

 the repulsive force greater than the attractive for 



