Part C: Application of Integration $($Elements $1.3)$

$4.$ The deflection $y$ of a simply supported beam with a concentrated load $P$ is $10kN$ at the midspan. Where $E$ is the elastic modulus, and I is the moment of inertia of the beam's cross section, the rectangular beam and $h=5mm$ and the total length of the beam is $5m.$ Find the maximum deflection and the deflection at $1\mathrm{.}25m$ from the right end.