2x^2 -1 can also be written as...?

Question

anonymous · Answer

I did this ... and I was able to get 2(x+1)(x-1) 

Not sure if I'm correct.

anonymous · Answer

You basically have to just factor that buddy up there..

anonymous · Answer

Thats the only way I see it being written.

anonymous · Answer

Wait. I think Im wrong. Double checking.

ranga · Answer

^^^ you can factor 2 out if it was 2x^2 - 2   but not when it is 2x^2 - 1

anonymous · Answer

thank you!

anonymous · Answer

Yeahh! I just realized that -1 !!! haha.

anonymous · Answer

So therefore, you would have to find two numbers that will give you -1 but added give you 0. Then factor. Right? @ranga

ranga · Answer

Using the identity: $$\Large a ^{2} - b^{2} = (a + b)(a - b)$$ we can write 
$$\Large 2x ^{2} - 1 = (\sqrt{2}x + 1)(\sqrt{2}x - 1)$$
But that introduces radicals even though it does factorize it.

anonymous · Answer

Okay! That was way out of my league! Thought I was on the right track.... when .... I clearly wasn't. Hahaa! We learn something new everyday don't we. Lol.

anonymous · Answer

Ranga, when your completed with this, would you be up to help me with a question of mine that I wish you could help me get the answer to? @ranga

ranga · Answer

rbeckford134: sure post it on a separate thread and message me the link.

anonymous · Answer

Sounds good bud! Ill post it now. Thanks!