y=-2x⼀(1+x2)^2的导数怎么求?

(求详解)
2024-11-23 19:12:11
推荐回答(2个)
回答1:

y=-2x/(1+x^2)^2
y' =-2[(1+x^2)^2 - 4x^2.(1+x^2) ]/(1+x^2)^4
   =2(3x^4+2x^2 -1)/(1+x^2)^4
   =2(3x^2-1)(x^2+1)/(1+x^2)^4
   =2(3x^2-1)/(1+x^2)^3

回答2:

y=-2x/(1+x^2)^2
y' =-2[(1+x^2)^2 - 4x^2.(1+x^2) ]/(1+x^2)^4
=2(3x^4+2x^2 -1)/(1+x^2)^4
=2(3x^2-1)(x^2+1)/(1+x^2)^4
=2(3x^2-1)/(1+x^2)^3