y'=z+xz'\\ x(z+xz')=2\sqrt{x^2+(xz)^2}+xz\\xz'=2\sqrt{1+z^2}\\ \dfrac{dz}{\sqrt{1+z^2}}=\dfrac{2dx}{x}\\ arcsh(z)=2lnCx\\ arcsh(\dfrac{y}{x})=2lnCx\\ \dfrac{y}{x}=sh(2lnCx)\\ y=x*sh(2lnCx)" alt="y=xz=>y'=z+xz'\\ x(z+xz')=2\sqrt{x^2+(xz)^2}+xz\\xz'=2\sqrt{1+z^2}\\ \dfrac{dz}{\sqrt{1+z^2}}=\dfrac{2dx}{x}\\ arcsh(z)=2lnCx\\ arcsh(\dfrac{y}{x})=2lnCx\\ \dfrac{y}{x}=sh(2lnCx)\\ y=x*sh(2lnCx)" align="absmiddle" class="latex-formula">