Question

How to solve the following using u-substitution. x^4+x^2+9=0?

Answer 1

I'm not sure if you meant to type "substitution" as there needs to be two equations for that to be possible. However, using factoring, we can get our answer of `x=+-sqrt3`.

Explanation:

Let's factor our equation into a perfect square binomial , then set it equal to `0` and solve for `x`:

`x^4+x^2+9=0`
`(x^2+3)^2=0`
`x^2+3=0`
`x^2=3`
`x=+-sqrt3`

Hope this helped!!