PROPERTIES of the CIRCLE. 5t 
——S—- ——OCr n-— . . 
bo — 6" 4+. ch —-¢™ + &e. to 4 3 terms, is equal to 7 X 
~ 
162+3-4 ioe x Pepi er kee when r7=1 
pt2 p+6 ptio : 2p—2 
. o 
i 2 2 2 2 I 
1S) Sy 0X : x r= nx 
4 6 rer 22 
2 
pH2-pHG...toap—2 : 
p X 4a. Hence the fummation of 
_ ani endlefs variety of feries, of which the terms are powers of the 
fines and.cofines of angles ; and though they do not confift of an 
infinite number of terms, they may confift of any number of 
n2—T 
-terms whatever, fince 
may be equal to any given number 
an wellae a aiheOrS pp) expreflion 1 X BRST te OPO 
tet A Se * £.2.3-4.+.t0% 
pt+2.p+6...to2p—2 
2 2 2 
i geree 2 T 4 
X ay, sax p X ger » when 
hia 2 + Bees toe 22 
te 
= is equal to an even number, or / is a multiple of 2 by an even 
number. But when is an odd number, it is equal to 2 X 
a 2 
ane, se which muft.then be ufed. 
—2 
2,4-. to S=3 2.3 
be 
G2 , THE 
