Factor Completely: 2x^4-2?

Question

I'm not sure if i am right, but i get 2(x^2-1)(x^2+1).

Answer 1

Well, work it out.

2(x^4 + x^2 - x^2 - 1) right?

Middle ones cancel out.

2 (x^4 - 1)  

Then multiply out.

2x^4 -2

So I'd say you got it right.  When in doubt, rework the problem and see if you get it right.  

P.S.  If you hadn't gotten it right I wouldn't have written out an answer.  ;)  But it's good to know how to check it like that so that if you're on a test you can take the moment and do it.  I've found more mistakes that way.

Add:  Heh.  First answer is right.  x^2-1 can be factored out as well... *face palms*

Answer 2

2(x-1)(x+1)(x^2+1)

Answer 3

Question Number 1 :

For this equation 2*x^4 - 2 = 0 , answer the following questions :

A. Use factorization to find the roots of the equation !

Answer Number 1 :

The equation 2*x^4 - 2 = 0 is already in a*x^4+b*x^2+c=0 form.

In that form, we can easily derive that the value of a = 2, b = 0, c = -2.

1A. Use factorization to find the roots of the equation !

  2*x^4 - 2 = 0

  <=> 2 * ( x^2 - 1 ) * ( x^2 + 1 ) = 0

  <=> 2 * ( x - 1 ) * ( x + 1 ) * ( x^2 + 1 ) = 0

  We got x1^2 = 1 and x2^2 = -1

  To get the root, remember x1 = sqrt( 1 ) , x2 = sqrt( -1 ) ,  x3 = -sqrt( 1 ) and x4 = -sqrt( -1 )

  So we got the answers as x1 = 1 , x2 = i ,  x3 = -1 and x4 = -i ,