Question

ln平方（1+x平方）求导,

Answer 1

求导就用链式法则一步步来,

[ln(1+x^2)]^2 '

= 2ln(1+x^2) * [ln(1+x^2)] '

= 2ln(1+x^2) * 1/(1+x^2) * (1+x^2)'

= 2ln(1+x^2) * 1/(1+x^2) * 2x

=4x/(1+x^2) *ln(1+x^2)