220 
MEMORIAS CIENT IFICAS I LITERARIAS 
4 X i d X 1 + yJ 1 — X* 
dy =\ 1 = . = d x 
“ (1 — y/l — a? 4 ) 2 \/ 1 — a;\/l — ar* 
1 
7. u=— — L (i — 2 ) — L (i-fz)-|-2 A: 7t ; ] (Jordan, 239) 
2 1 
1 / — 1 1 \ J dz 
rf “ = T7 — 
8. y=zx hx (Laurent, 82) 
Sea u =L x\ resulta la funcion reducida 
y = x" 
dy d x 
L y~u Lx y — = L x d u -f- u — 
y x 
d x d x\ dx 
dy =y 1 1. x — - -f L x — \—y . 2 L x — 
X X X 
d y—x. Lv L x 2 — = 2 x Lx ~ 1 L x d x. 
x 
(Serret, 50) 
Sea u=tg v, y p 
7t 
x 
2 
queda y=hu dy 
