Question 1157185
{{{system(y^2+2y-1=x,y>0)}}}


{{{(y-1)^2=x}}}

{{{y-1=0+- sqrt(x)}}}

{{{y=1+- sqrt(x)}}}

{{{f^-1(x)=1+sqrt(x)}}}  , also {{{f^-1(x)>=1>0}}}