REGLAS DE DIFERENCIACION 
231 
d y= dmh 
d n+r tg \ x 
n+r tgix n—r tg £ x 
— = m . 
n — r tg f x n-j-r tg -§■ x 
n — r tg \ x 
• ’ • dy = 
1 
a-\-b cos x 
y — L tg (| Tc-f-i x ). (Greenhill, 51) 
_ sec* (£ Tr+i x). \ d x _ d x 
tg (i 71 + i x) 2 sen (£ * -j- \ x) cos (i * -f- \ x) 
d x d x 
— = = sec x d x 
sen it + x) cos x 
1 
6. y= .. ■ ■ (Cournot, 119) 
\/ r 2 2+r f cos x+r’ 2 
_ _ 3 
d y—d (r a -\-r * — 2 r r’ cos x) 2 =— \ (r 2 2 — 2 r r’ cos x) 2 
— rr’ sen x d x 
X d (r 2J rr ’ 2 — 2 /• r’ cos x) — -- ~ - ■ . . 
V (r 2 — 2 r r cos x-\ r 2 ) 3 
7. 
2 /=arc tg 
X t g JL 
a +6 5 2 
(Rouche-Levy, 61) 
