Discussion
Let [x] = x2 – 2. If [2] - [x] = x2, then x =
| (A) | √2 |
| (B) | ... |
| (C) | ... |
| (D) | ... |
| (E) | ... |
| (F) | ... |
The solution is
Posted: 01/25/2013 10:34
Wht only substitute in the left side id The equation?
Posted: 01/26/2013 00:02
Not sure what your question was Andres.
Posted: 01/26/2013 10:48
In the explanation they only substitute the value of x in the left side:
2-x = x^2
The left side is 2-x
The rigth side is x^2
You need to substitute x = x^2 - 2 for all valúes of x in both sides of The equation?
The explanation goes:
2- (x^2-2) = x^2
If You substitute x in The right You should get : (x^2-2)^2?
Hope that I explaned better!
2-x = x^2
The left side is 2-x
The rigth side is x^2
You need to substitute x = x^2 - 2 for all valúes of x in both sides of The equation?
The explanation goes:
2- (x^2-2) = x^2
If You substitute x in The right You should get : (x^2-2)^2?
Hope that I explaned better!
Posted: 08/01/2013 06:21
I agree with Andres. I don't know if I did the question wrong, but get 2 as the answer. I went about the problem in 2 ways, here is what I did:
1) I saw that both equations were equal so I discarded the first one solving for x and just solved for the roots of
x^2-x-2=0 which are 2, -1
So I chose 2 as the answer.
2) the second way was when I realized that maybe I might have to substitute for x and I followed what Andres did:
x^2-4 x+4 = x^2-4 which still gives back the answer as 2.
Maybe it's the way I'm reading it but I think my work is right?
1) I saw that both equations were equal so I discarded the first one solving for x and just solved for the roots of
x^2-x-2=0 which are 2, -1
So I chose 2 as the answer.
2) the second way was when I realized that maybe I might have to substitute for x and I followed what Andres did:
x^2-4 x+4 = x^2-4 which still gives back the answer as 2.
Maybe it's the way I'm reading it but I think my work is right?
Posted: 08/01/2013 08:58
This question does not look right. Andres and Mike, let us check and get back.
Posted: 08/12/2013 16:22
Joel, thanks for notifying us. We fixed it, it will be in the next update. Thanks.
Posted: 08/27/2013 20:47
Next update not out yet
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