Y = x^3/3 - 5/2*x^2 + 4x - 1
y ' = 1/3*3x^2 - 5/2*2x + 4 = x^2 - 5x + 4
y ' = 0 ==>
x^2 - 5x + 4 = 0
(x - 4) ( x - 1) = 0
x = 1
x = 4
+ max - min +
-------------( 1 ) --------------( 4) -------------> x
y(1) = 1/3 - 5/2+ 4 - 1 = 0,8(3) max
y(4) = 64/3 - 40 + 15 = - 3,(6) min