F ' (x) = (x^3 - 2*x^2 + x + 3) ' = 3x^2 - 4x + 1 ;
f ' (x) = 0;
3x^2 - 4x + 1 = 0 ;
D = 16 - 12 = 4
x1 = ( 4 + 2)/6 = 1 ∈ [ 0; 1,5]
x2 = ( 4 - 2)/6 = 1/3 ∈ [0; 1.5]
y (0) = 3; min
y (1/3) =(1/3)^3 - 2*(1/3)^2 + 1/3 + 3 = 1/27 - 2/9 + 1/3 + 3 =
= (1 - 2*3 + 9 + 3*27)/27 = 85/27 = 3,(148)
y (1) = 1 - 2 + 4 = 3; min
y (3/2) = (3/2)^3 - 2*(3/2)^2 + 3/2 + 3 = 27/8 - 18/4 + 3/2 + 3 =
= 3,375 - 4,5 + 4,5 = 3,375 max