求导数y=ln[(x+1)/(x-1)]^(1/2) y’={1/[(x+1)/(x-1)]^(1/2)}*(1/2)[(x+1)/(x-1)]^(-1/2)*[x-1-(x+1)]/(x-1)^2 =[(1/2)*(x-1)*(-2)]/[(x+1)*(x-1)^2] =1/(1-x^2)
