119 



Also 



-y.r -a^dr 



- sf) dx - 2a 



^ - 2a f V(2a - *) vers- 1 ^ 

 9 j a 





crcfore / t V<& - *V - V(2a* - rf) TI-I 



.' a 





Bj assuming vers~' - - 0, we may shew that 

 | V(2or *) vcrs" 1 *<&-- 



.ce 

 fore v i 



1 M. If :i vo a bra ,v the axis of x y ra- 



ni with one above the axis, and we require the < 



/ of the area bounded by the two branches and or- 

 * drawn at the distances c and h from the origin, wo 

 have 



J. y"* 

 y =0. 



We have hitherto supposed the axes rectangular; 



y arc oblique and inclined at an angle :igure 



111) will -sin taySx ultimatelv. 



fnnnuliB (I) and (2) of Art. Ill remsill true, for 



occurs as a i the numerator and denominator, 



be cancelled. 



