LOS METODOS DE IN TEGKACION 
= j d x - / cos x d x— x — sen x 
2. / confers en x d x=/ (1 — senx) dx=x f-cos x. 
0 r o , r l-cos2x , 
3. J sen 2 x d x = J — — d x 
= ~ J d x = / cos 2 x d x 
= — r- x — - sen 2 x 
Z 4 
4. 
/ cos 2 x d x = f- 
l-(-cos 2 x 
d x = 
x4- - 7 - sen 2 x 
4 
5. Otrometodo. (Humbert, I, 199). 
f x cos 2 x-|- / x sen 2 x=/ x (cos 2 x-[-sen x)=/ d x=x, 
fx cos 2 x-/ * sen 2 x = / x (cos s x— sen 2 x) = /* cos 2 x = -i- sen 2 x, 
LJ 
sumando i restando, se obtiene: 
/ cos 2 x d x= -i- x + -i- sen' 2 x (Daries, 116) 
/ sen 2 x dx= ]- x — -i- sen 2 x (Bowser, 246) 
