Find all real values of xxx satisfying x4−5x2+4=0x^4 - 5x^2 + 4 = 0x4−5x2+4=0.
x=±1,±2x = \pm 1, \pm 2x=±1,±2
x=1,2x = 1, 2x=1,2
x=±sqrt5x = \pm \\sqrt{5}x=±sqrt5
x=±4x = \pm 4x=±4