Question 18The set of all real numbers $x$ for which $$ x+\sqrt{x^2+1}-\frac1{x+\sqrt{x^2+1}} $$ is a rational number is the set of allintegers $x$rational $x$real $x$$x$ for which $\sqrt{x^2+1}$ is rational$x$ for which $x+\sqrt{x^2+1}$ is rational