Can any one solve this problem?!

8. (14 points) Let L be the line segment with endpoints at (1, 2, 3) and (-1, 1, 1). A light source at is at the point P = (0, 4, 5). The ground is modeled by the plane a ty-z+3 = 0 and the light casts a shadow of the line segment onto the ground. Give a parametrization of the shadow