40. y 
y 
41. y 
42. y 
Sea 
LOS METODOS DE INTEGRATION 
61 
i r , 1 
— / sen z d z = — - — - cos a x 
a J a 
= /■ 
dx 
sen x 
Sea cos x = z 
c 
cos 2 x = l — z 2 , sen x = / l-z 2 
d z 
sen x d x = d z dx=- 
sen x 
-a --I 
! 1 — cos X 
7 = Lt 8’-9- x 
1 -+■ COS X 
(Francoeur, 381) 
= / cos x d x. Sea sen x = z . ' . cos xdx = d z 
y == / d z = z = sen x . (Roberts, 7) 
= ^ — d X = [■ 
J cos x J 
cos x d x 
cos 2 x 
z = sen x . ■ . 1 — z 2 = cos 2 x , 
, i f dz T 1 / 1 
d r L = cos x d x, y= ^ = F [/ -7 
+ z 
v? 
L 1/ : senx = L cot (-- x 
■sen x V 4 
1 ^ 
~ x ) 
43. y == / sen x cos x d x . Sea sen x = z . • . cos xdx = dz 
