Question

X^4-x^2-42=0
need to solve equation and find solution set

Answer 1

That's a quadratic equation in
`x^2`, which means we get an extra square root and
`\pm` at the end.


`x^4 - x^2 - 42 = 0`

We factor,


`(x^2 - 7)(x^2+6) = 0`


`x^2 = 7 \quad \textrm{or} \quad x^2 = -6`


`x = \pm √(7) \quad \textrm{or} \quad x = \pm i √(6)`