Question

y=(x+1)^2/3(x-5)^2的极值,

Answer 1

y'=(((x+1)^2)'*3(x-5)^2-(x+1)^2*(3(x-5)^2)')/((3(x-5)^2)^2)=(-4(x+1))/((x-5)^3)

y'＞0→-1＜x＜5

y'＜0→x＜-1或x＞5

(-∞,-1)减(-1,5)增

在x=1处取极大值 f(-1)=0