Derive the bending moment and shear force expressions and explain how they vary along the length of the beam for a cantilever beam with a point load

Derive the bending moment and shear force expressions and explain how they vary along the length of the beam for a cantilever beam with a point load at the end of the beam, beam length L and load weight W. then referring to Engineer's Bending Equation, explain how the bending stress varies across the cross-section of the beam