  In this paper, we studied the behaviour of compact relativistic objects with
anisotropic matter distribution considering quadratic equation of state of
Feroze and Siddiqui (2011). We specify the gravitational potential Z(x) in
order to integrate the fields equations and there has been calculated the
energy density, the radial pressure, the anisotropy and the mass function. The
new solutions to the Einstein-Maxwell system of equations are found in term of
elementary functions. For n=2, we have obtained the expressions for mass
function, energy density, radius and metric functions of the model of
Thirukkanesh and Ragel (2012) with polytropic equation of state.
