Question

判断并证明函数f(x)=ln(1-x)/(1+x)的奇偶性

Answer 1

f(x)+f(-x)=ln[(1-x)/(1+x)]+ln[(1+x)/(1-x)]
=ln{[(1-x)/(1+x)]×[(1-x)/(1+x)]}
=ln1
=0
f(-x)=-f(x)
定义域(1-x)/(1+x)>0
(x-1)(x+1)