148 
MEMORIAS C1ENTIFICAS I L1TERARIAS 
= / -- sen (90°— -x) d (90° — x) 
= cos (90° — x)=sen x 
31. / cos a x d x = — / cos a x d a x = — sen a x . 
J a J a 
32. J tgxdx = /- 
sen x d x 
cos x 
-/ 
dcosx 
cos x 
Lcos x 
qq f x j r & sen x r 
33 / cot x d x = — - = L sen x 
J J sen x 
oa f a f dx f cosxdx f d 
34. / secx d x= = — — 
J J cos x J cos 2 x J 1 - 
cos x d x 
d sen x 
sen z x 
= L l/A± sen - s - = L tg 1 
1/ j ^ ° 
■sen x 
T x +x ) 
35. f cosec x d x = I — X = ( — - — - 
J J sen x J 1 — 
d cos x 
cos x 
L yi+cosx i 
X 1 — cosx ° 2 
XII. / sec 2 x d x . 
f sec 2 xdx= P \ ■ ■ dx= f- 
J J cos 2 x 
cos 2 x-fsen 2 x 
d x 
W 
? cos v d sen x — sen x d cos x 
cos z x 
I 
