Bonjour,
f(x) = (x³+2) / ( x²-1).
dérivée :
f(x) = u/v
f '(x) = (u'v - uv')/v²
u' = 3x²
v' = 2x
f '(x) = [3x²(x² - 1) - 2x(x³ + 2)] / (x² - 1)²
f '(x) = (3x⁴ - 3x² - 2x⁴ - 4x)/[(x - 1)(x + 1)]²
f '(x) = (x⁴ - 3x² - 4x)/[(x - 1)(x + 1)]²
f '(x) = [x(x³ - 3x - 4)]/[(x - 1)(x + 1)]²