where E is Young’s modulus, A is the cross-sectional area of each member, l is the span of the truss, s is the length of each member, h is the height of the truss, P is the applied load,  is the angle at which the load is applied, x1 and x2 are the horizontal and vertical displacement of the free node, respectively.

Find the values of x1 and x2 that minimize the potential energy when E = 207x109 Pa, A = 10-5 m2, l =1.5 m, h = 4.0 m, P = 104 N and -where E is Young’s modulus, A is the cross-sectional area of each member, l is the span of the truss, s is the length of each member, h is the height of the truss, P is the applied load, 　 is the angle at which the load is applied, x1 and x2 are the horizontal and vertical displacement of the free node, respectively.　

Find the values of x1 and x2 that minimize the potential energy when E = 207x109 Pa, A = 10-5 m2, l =1.5 m, h = 4.0 m, P = 104 N and 