所以
log(1/2)[(1+ax)/(-x-1)]+log(1/2)[(1-ax)/(x-1)]=0
即log(1/2)[(1+ax)/(-x-1)*(1-ax)/(x-1)]=0
所以(1+ax)/(-x-1)*(1-ax)/(x-1)=1
1-a^2x^2=1-x^2
所以
log(1/2)[(1+ax)/(-x-1)]+log(1/2)[(1-ax)/(x-1)]=0
即log(1/2)[(1+ax)/(-x-1)*(1-ax)/(x-1)]=0
所以(1+ax)/(-x-1)*(1-ax)/(x-1)=1
1-a^2x^2=1-x^2