Solve x4−7x2+12=0x^4 - 7x^2 + 12 = 0x4−7x2+12=0
x=±2,±3x = \pm 2, \pm \sqrt{3}x=±2,±3
x=±2x = \pm 2x=±2 only
x=±3x = \pm \sqrt{3}x=±3 only
x=2x = 2x=2 or x=3x = 3x=3