80 
MEMORIAS CIENTIF1CAS I LITERAKIAS 
s/ X 5 
X 
sen y. 
dx 
x/ x 2 — a 2 
seny 
seny 
1 a 1 x 
— arc cos — = - — arc sen 
a x a a 
(H. Cox, 35) 
6. — 7- — • Sea x = a sen 2 &-\-8 cos 2 d> 
W(a-x)(x-/8) 
. • . a — x = (a — f3) cos 2 (p, x — f3 = (a — /3) sen 2 (j), (1) 
(a — /3) (x— /3)—(a — /3) 2 sen 2 <p cos 2 <p 
d x=2 (a— /5) sen ^ cos d 0 
V = ( 2(a - # sen ^ cos </> d r 2A 2 
" ^ (a — /3) sen 0 cos </> 7 
Dividiendo (1): 
sen 2 ^ _ x-fl . 
COS 2 ^ a+x & ^ 
-'VrE 
-£ 
X 
! X — 13 
x 
• ^ = arc tg j/ 
(Roberts, 17) 
f x 2 d x 
J Vl— X 2 
Sea x = cos z . • . d x = — sen z d z 
