890 MEMORIAS CIENTIFICAS I LITERARIAS 
dx 
COS X 
sen 
T * / 1 1 ■ 
Ltg;T-+ - Xj 
10 . 
dx 
d X 
COS^ X 
sen X cos X / senx 
L tg X 
COS X 
(Stoffaes, 1^1) 
11 . 
d X 
1 -• cos X 
r dx 
J 2 sen'^ 4" - 
12 . 
r o 1 ^ 1 1 
= J cosec“ — X d — X = — cot ~ x 
f 'dx 1 r 1 r 
Ja(l+cosx) aj 
d tg ^ X 
1 1 
13,‘ f • Reduzcamos a 4-x: 
a + b cos X 2 
a+bcosx = a', sen 2 -^x + cos‘^-^x j+b j cos^ 4*^) 
1_ 
2^V 
= (a + b) cos“ -i- X + (a — b) sen*-^ ~ x 
