bjr
g(x) = (5x + 7)²
soit g(x) = (u(x))²
avec u(x) = 5x + 7
donc u'(x) = 5
=> g'(x) = (u(x))² = 2 * u' * u = 2 * 5 * (5x+7)
=> g'(x) = 10 (5x + 7)
vérif avec autre calcul :
g(x) = (5x + 7) (5x + 7)
= u x v
g'(x) = u'v + uv"
ici u = 5x + 7 => u' = 5
v = 5x + 7 => v' = 5
donc g'(x) = 5 (5x + 7) + 5 (5x + 7) = 10 (5x + 7)
