f(x) - (2x -3) = (-2x² +5x-2 + 2x² -2x + 3 - 3x )/(1-x) = 1/(1-x)
signe de f(x) - (2x - 3)
x 1
1/(1-x) + | -
f(x) au dessus f(x) en dessous
f(x) = x³ + x² + 1
t(h) = (f(2+h) - f(2))/h = [((2+h)³ + (2+h)² + 1) - 13]/h = (h³ + 7h² + 4h)/h = h² + 7h + 4
f'(2) = lim (h² + 7h + 4) = 4
h->0
