Y=(x-10)^2[100-(x-10)^2]

问题描述:

Y=(x-10)^2[100-(x-10)^2]
求x为何值时,
Y最大

用均值不等式
Y=(x-10)^2[100-(x-10)^2]
≤{(x-10)^2+[100-(x-10)^2]}^2/4
=625