**Solution**

From the previous exercise (Calculation example-Calculate member diagrams) published (17 January 2017), we work for the section 0<x<L/2.

The Shear force is S(x)= P/2

The Moment is M(x)= P/2 x

The Slope and the Elastic Curve are:

Due to symmetry, boundary conditions are:

We calculate the slope: