A built-in beam ACB of span L carries a concentrated load W at C a distance a from A and b from B. If the flexural rigidity of the beam is EI, use the principle of superposition to determine the support reactions.
Ans. R_{ A }=W b^{2}(L+2 a) / L^{3}, R_{ B }=W a^{2}(L+2 b) / L^{3}, M_{ A }=W a b^{2} / L^{2}, M_{ B }=W a^{2} b / L^{2}.