Réponse :
Bonsoir
Explications étape par étape
5) a) f(x) = x² - 5x +1 b) f(x) = x + 1/x
f'(x) = 2x - 5 f'(x) = 1 - 1/x² = (x²-1)/x² = (x-1)(x+1)/x²
6) a) f(x) = 3x² - 4x + 2 b) f(x) = x³ + 2x + 1
f'(x) = 6x - 4 f'(x) = 3x² + 2
7) a) f(x) = 2x + 1 + 1/x b) f(x) = 2x² -1/x
f'(x) = 2 - 1/x² = (2x² - 1)/x² f'(x) = 4x + 1/x²
8) a) f(x) = (1/4)x² + 4x + 3 b) f(x) = x³ + 1/2x
f'(x) = (1/2)x + 4 f'(x) = 3x² - 2/(4x²)= 3x² - 1/(2x²)
9) a) f(x) = (1/3)x³ + x² b) f(x) = 4 - 1/x
f'x) = x² + 2x f'(x) = 1/x²
10) a) f(x) = x³ - x + 1 b) f(x) = -0,5x² + 2,5x
f'(x) = 3x² - 1 f'(x) = -x + 2,5
11) f(x) = x³ + 5x² - 4x + 3
f'(x) = 3x² + 10x - 4
12 a) f(x) = -x² + 2x b) f(x) = (1/3)x² + 4x + 7
f'(x) = -2x + 2 f'(x) = (2/3)x +4
