y = x^2/2 - 14x^(3/2)/3 + 12x + 5
y`=0
x-7sqrt(x)+12=0
sqrt(x)=3 или sqrt(x)=4
x=9 или x=16
x=16 - точка минимума
y(16)=(16^2/2)-(14/3)*(16)^(3/2)+12*16+5
y(16)=325-298(2/3)=[b]26(1/3)[/b]
y(9)=(9^2/2)-(14/3)*(9)^(3/2)+12*9+5
y(9)=55/2