P$7\mathrm{.}3$ For the beam shown,

$($a$)$ derive equations for the shear force V and

the bending moment M for any location in the

beam. Place the origin at point A $.)$

$($b$)$ use the derived functions to plot the shear$-$

force and bending$-$moment diagrams for the

beam. Specify the values for key points on the

diagrams.

FIGURE P$7\mathrm{.}3$