Численный ответ
x1 = 1.41421356237000 x2 = -1.41421356237000 x3 = 0.707106781187000 x4 = -0.707106781187000
x1 = 1.41421356237000 x2 = -1.41421356237000 x3 = 0.707106781187000 x4 = -0.707106781187000