#y=sqrt((1-x)/(1+x))#
#y=sqrt((1-x)/(1+x)xx(1-x)/(1-x))#
#y=sqrt((1-x)^2/(1-x^2)#
#y=(1-x)/sqrt(1-x^2)...to(A)#
#"Using "color(blue)"Quotient Rule"#
#(dy)/(dx)=((sqrt(1-x^2))(0-1)-(1-x)(1/(2sqrt(1-x^2))
(-2x)))/((sqrt(1-x^2))^2)#
#(dy)/(dx)=(-sqrt(1-x^2)+((1-x)x)/sqrt(1-x^2))/(1-x^2)#
#(1-x^2)(dy)/(dx)=(-(1-x^2)+(1-x)x)/sqrt(1-x^2)#
#(1-x^2)(dy)/(dx)=(-1+x^2+x-x^2)/sqrt(1-x^2)#
#(1-x^2)(dy)/(dx)=(-1+x)/sqrt(1-x^2)#
#(1-x^2)(dy)/(dx)=-(1-x)/sqrt(1-x^2)...toUse(A)#
#(1-x^2)(dy)/(dx)=-y#
#(1-x^2)(dy)/(dx)+y=0#