Equillibrium of forces

Question

Forces X, Y, Z act along the three lines given by the equations

y = 0, z = c; z = 0, x — a; x=0, y — b;

prove that pitch of the equivalent wrench is

If the wrench reduces to a single force, shew that the line of action

of the force must lie on the hyperboloid

(x-a)(y-b)(z-c)-xyz = Q

Answer 1

(Following, awaiting your response)