Domain: as a logarithmic function, it must be (1+x)/( 1-x)>0, (x+1)/(x-1) <; 0, as a score, x≠ 1, x∈(- 1,1);

( 1)f(-x)= log2[( 1-x)/( 1+x)]= log2[( 1+x)/( 1-x)]。

(2) logarithmic function, base = 2 >；; 1, increasing function, f(x)>0, (1+x)/(1-x) >1,depending on the domain,1-x > 0， 1+x & gt； 1-x，2x & gt0，x & gt0

x∈(0， 1)