Найдите наименьшее значение функции

-x^2 + 6x - 5 = 0

ymax = - D/4a = 2, vetvi napravleni vniz.

Togda sqrt{ - x^{2} + 6x - 5} < 3, D (x) prinadlezhit [x1; x2] = [1; 5]

togda modul otr vir = 3 - sqrt{-x^{2}+6x-5}

f (x) = 3 + x^3+6x^2, D (x) = [1; 5]

F' (x) = 3x^2 + 12x

F' (x) = 0 = > x (x+4) = 0, x=0, x=-4

F'' (x) = 6x+12

F'' (0) = 12 > 0 = > f (x) vozrastaet pri vseh x prinadlezhashih ODZ

xmin = 1