Find all real xxx such that x4−10x2+9=0x^4 - 10x^2 + 9 = 0x4−10x2+9=0.
x=±1,±3x = \pm 1, \pm 3x=±1,±3
x=1,3x = 1, 3x=1,3
x=±10x = \pm\sqrt{10}x=±10
x=±9x = \pm 9x=±9