求函数y=(x+5)^3(x-10)^2的极值
问题描述：
求函数y=(x+5)^3(x-10)^2的极值
答
y'=3(x+5)^2(x-10)^2+2(x-10)(x+5)^3
=(x-10)(x+5)^2[(3x-30)+2x+10]=0
=(x-10)(5x-20)(x+5)^2>0
x>10,x