Could you tell me the process of solving the problem?

Given:
[tex]Ln8=\frac{2\pi m\xi}{\sqrt{1-\xi^2}}[/tex]m=250
Required:
Find the value of
[tex]\xi[/tex]Explanation:
The value of ln8 is:
[tex]ln8=2.079[/tex][tex]\begin{gathered} 2.079=\frac{2\times3.14\times\xi}{\sqrt{1-\xi^2}} \\ 2.079(\sqrt{1-\xi^2})=6.28\xi^ \end{gathered}[/tex]Take the square on both sides.
[tex]\begin{gathered} 4.322(1-\xi^2)=39.44\xi^2 \\ \frac{1-\xi^2}{\xi^2}=\frac{39.4384}{4.322} \\ \frac{1}{\xi^2}-1=9.125 \\ \frac{1}{\xi^2}=9.125+1 \\ \frac{1}{\xi^2}=10.125 \end{gathered}[/tex]