y=((1+x)/(1-x))^1/2y'=1/2((1+x)/(1-x))^(-1/2)*((1+x)/(1-x))'=1/2((1+x)/(1-x))^(-1/2)*((1+x)'(1-x)-(1+x)(1-x)')/(1-x)^2=1/2(1+x)^(-1/2)/(1-x)^(-1/2+2)*(1*(1-x)-(1+x)(-1))=1/[2(1+x)^(1/2)(1-x)^(3/2)]*(1...