A perfect square trinomial is in the form $\displaystyle{{r}}^{{2}}+{2}{r}{s}+{{s}}^{{2}}\usepackage{cmbright}\Huge\$ or $\displaystyle{{r}}^{{2}}-{2}{r}{s}+{{s}}^{{2}}\usepackage{cmbright}\Huge\$ . The constant term must be a perfect square. The constant 2 is not a perfect square, so this is not a perfect square trinomial.