## Integration

Show that $\int \frac{x}{\sqrt{x^2-4}}dx=\sqrt{x^2-4}+c$

Hence find the exact value of $\int_{\sqrt{5}}^{\sqrt{8}}\frac{\ln (x^2-4)}{\sqrt{x^4-4}}dx$

I could do the first part but no idea about the 2nd part.