The plane truss is made of three members and is loaded with force P as shown. Each member has the same E, A and L as shown below. Determine, a) the displacements at node 1, b) the reaction forces. Show all your work. Truss Element Stiffness Matrix [K]_XY^(e) = AE/L [cos^2 theta sin theta cos theta -cos^2 theta -sin theta cos theta sin theta cos theta sin^2 theta -sin theta cos theta -sin^2 theta -cos^2 theta -sin theta cos theta cos^2 theta sin theta cos theta -sin theta cos theta -sin^2 theta sin theta cos theta sin^2 theta] Recall that if A = [a b c d] then A^-1 = 1/|A| [d -b -c a] {R} = [K]^(G) {U} - {F}