The analytical dependence of the deflection of a statically determinate plane elastic truss with a uniform loading of the upper zone has been found. Forces in rods were determined using the joint isolation method. A system of equilibrium equations has been compiled in matrix form. Midspan deflection has been calculated based on the Maxwell-Mohr formula. All character conversion has been executed in the Maple computer algebra system. The method of induction on the number of panels in the truss was used. Recurrent equations for general members of the sequences of coefficients were obtained and solved using the genfunc operators package from the Maple system. The dependencies of the forces in the rods of the truss and of its deflection on the number of panels are non-monotonic, which is generally characteristic of lattice struts. We have also shown that for an odd number of panels the truss is instantaneously variable. The distribution of possible nodal velocities is given for this case.