\(\begin{array}{l}
mg\,x\, = Mg\left( {\frac{{.\ell }}{2} - x} \right)\\
\Rightarrow mx = M\frac{\ell }{2} - Mx\\
m = \left( {M\frac{\ell }{2}} \right)\frac{1}{x} - M\\
y = \alpha \frac{1}{x} - C,\,\,\,\,\,\,\,\,\, straight\,\, line\,\, equation.
\end{array}\)