Respuesta :
the answer is x4 + 2x2 + 2,
proof
if a is a (real) is a root of x4 + 2x2 + 2, so
a4 +a2 +2 =0, it is impossible, because a4>0, a2>0 and 2>0
a4 +a2 +2 must be >0, so x4 + 2x2 + 2 doesnt have real roots
proof
if a is a (real) is a root of x4 + 2x2 + 2, so
a4 +a2 +2 =0, it is impossible, because a4>0, a2>0 and 2>0
a4 +a2 +2 must be >0, so x4 + 2x2 + 2 doesnt have real roots