Arcadia Prep

Links

Let [x] = x2 − 2. If [2] − [x] = x2, then x =

Let [x] = x² − 2. If [2] − [x] = x², then x =
(A)

(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Nova Math - Problem Set D: Defined Functions

Replies to This Thread: 1 | ----

Let [x] = x2 − 2. If [2] − [x] = x2, then x =

Posted: 10/08/2013 12:34

I'm confused with how you got to 2-(x^2-2)=x^2.

I attached how far I got before I began to get stuck. I need to brush up on factoring I think?

Contributor

Reply 1 of 1
Replies to This Thread: 0 | ----

Posted: 10/08/2013 16:04

Tiffany, here is the continuation of what you worked out. You need to factor the minus sign into the parentheses (x^2-2).

Replies to This Thread: 1 | ----

Let [x] = x2 − 2. If [2] − [x] = x2, then x =

Posted: 10/20/2013 13:29

How do you get from x^2-2 in the first step to x^2+2 in the second step? I just don't understand why the jump from - to + ?

Contributor

Reply 1 of 1
Replies to This Thread: 0 | ----

Posted: 10/20/2013 18:47

Pamela, we simply multiplied the negative sign, which you should think of like -1, into the parentheses.

So, for example: -(x-y) = -1*(x-y)=-x+y

Replies to This Thread: 0 | ----

Let [x] = x2 − 2. If [2] − [x] = x2, then x =

Posted: 10/20/2013 20:20

Thanks very much for clarifying, I'm very rusty even at basic math laws right now. Much appreciated.