Factoring with the quadratic formula

[Checkfate]

I have a huge headache and I can't understand why this works... I am reviewing the quadratic formula so that I can solve trig questions, but I am stuck on this one part...

The point is to factor $$x^2+2x-1$$

I ( and the textbook ) use the quadratic formula to get the roots of it and come up with

$$-1\pm\sqrt{2}$$

How do I use this to factor into $$(x+1-\sqrt{2})(x+1+\sqrt{2})$$?

I remember the quadratic formula as being more useful for solving quadratics where 1 side =0... I don't remember factoring with it! Can someone help? I would try to figure it out on my own but my head is spinning and I am under time pressure at this point. Thanks a lot guys.

I really do appreciate the help that I receive on these boards.

 

[Integral]

The quadratic formula gives you 2 roots r₁ and r₂ you then get the factors from

(x - r₁) (x - r₂) You then need to check your work by multiplying the 2 factors to ensure that you get back your starting quadratic.

 

[Checkfate]

Thankyou Integral! You helped me remember :)