# Simple Working Example Of HTML5 Mathml

If $y=\left(x+\sqrt{1+{x}^{2}}{\right)}^{n}$ , then $\left(1+{x}^{2}\right)\frac{{d}^{2}y}{{\mathrm{dx}}^{2}}+x\frac{\mathrm{dy}}{\mathrm{dx}}$ is?