y=(x+1)(x-1)(x-2)求导
问题描述：
y=(x+1)(x-1)(x-2)求导
答
y' = (x+1)'(x-1)(x-2)+(x+1)(x-1)'(x-2)+(x+1)(x-1)(x-2)'
= 1*(x-1)(x-2)+(x+1)*1*(x-2)+(x+1)(x-1)*1
= ……