(1)当 x>0 时,求函数y = x^2 + 3/x 的最小值;
a = x^2
b = 3/(2x)
c = 3/(2x)
a*b*c = 9/4
a + b + c = x^2 + 3/x 当且仅当 a = b = c 即 x = (3/2)^(1/3) 时取得最小值,所以原函数最小值为 3*(3/2)^(1/3)
(2)当 0