How do you factor #y= x^4 + 5x^2 - 6# ?
We notice that all terms containing the variable
so to simplify things initially we will replace
which can easily be factored as:
The first factor,
but the second,
Perhaps it will help if I rewrite this expression for
This is something we can factor pretty easily.
Just substitute back to get
And now, the last step is to factor the second bit which is a difference of two squares: