A simple beam ABC having rectangular cross sections with constant height h and varying width b x supports a concentrated load P acting at the midpoint (see figure). How should the width b x vary as a...

A simple beam ABC having rectangular cross sections with constant height h and varying width b_x
supports a concentrated load P acting at the midpoint (see figure).

How should the width b_x
vary as a function of x in order to have a fully stressed beam? (Express b_x
in terms of the width b_B
at the midpoint of the beam.)