Summation of Infinite Series. 35 
2 - JL. _ - Sec. == 1 + 4- A ; therefore the fum required = 
2 - 45*7 
4_ 4, 4 A as before. In the fame manner we may apply the cor- 
rection in all other cafes. Although, therefore, the feries 
j _ 1 4- 1 _ 1 + &c. or - 1 + 1 - 1 + 1 - &c. have no determi- 
nate value in the abftracl, yet the given feries will fix its value 
by pointing out the quantity from which the feries mu ft have 
been originally produced. 
E x 
