For the beam and loading shown, (a) Use discontinuity functions to write the expression for w(x). Include the beam reactions in this expression. (b) Integrate w(x) twice to determine (x) and M(x). A (c) Use V(x) and M(x) to plot the shear- force and bending-moment diagrams. y 4 ft 2800 lb 7750 lb*ft 3ft C 780 lb/ft 8 ft FIGURE 3 D 3 ft E X