Question

How do you solve using the completing the square method `x^2-4x+2=0`?

Answer 1

`y=(x-2)^2-2`

Explanation:

The completing the square form is:
`y=(x+a)^2+b`

The "a" term will be equal to the middle term divided by two. I.e. `-4/2=-2`.

This means that you now have the following:

`y=(x-2)^2+b`

Because the completing the square form is equivalent to your original equation you have:

`x^2−4x+2=(x-2)^2+b`
`x^2−4x+2=x^2-4x+4+b` <-- I expanded the right-hand side
`b=-2` <--After simplifying you can find the "b"-term