Math IIC Confusion... Collegeboard actual test

Test Preparation
1

<p>I saw a free Math IIC Test from collegeboard posted on some website for free at some Texas school so i printed it out and I got a 790 which is really freaking close to an 800. I skipped 2 problems and got 4 wrong. I got most of the ones wrong through stupid errors like not reading coordiate points right. Anyways. I was really confused with this one problem and I have seen on this practice test. It’s</p>

<li>The set of all real Numbers x such that sqrt(x^2) = -x consists of…
A) zero only
B) Nonpositive numbers only
C) Postive Real numbers only
D) All Real Numbers
E) No Real Numbers</li>
</ol>

<p>The answer was B but i think it’s D</p>

<p>Okay. Here’s my “wrong” method which I thought was right. well first I said okay, Zero works. I went on to B and i pluged in (-x) into the sqrt(x^2) and so i got abs(x) which ±x so -x is right in that part. Saved it. went on to C. I put postitive sqrt(x^2) and guess what I got, abs(x) again. So I assumed since A B and C both work and there are real numbers, I chose D.</p>

<p>If there is supposed to be an “actual” way to do this problem… please tell me SOOOOOOOOOOON because I really need to know.</p>

2

<p>i used my calculator for this question. did you get number 41?</p>

3

<p>Where did you find this test? I want to take it.</p>

4

<p>Never mind I found it.</p>

<p>Can't post the link though, unless it's not against the rules.</p>

5

<p>post ittt...</p>

6

<p>yea u can post it
not against any rules...</p>

7

<p>Found real SAT II M1 & M2 tests for free download. Anyone know where to find others?</p>

<p><a href="http://bealonghorn.utexas.edu/fresh...ission/testing/%5B/url%5D"&gt;http://bealonghorn.utexas.edu/fresh...ission/testing/&lt;/a>, bottom of the page, you can download pdf's of official College Board practice tests for Math 1 and Math 2. These are definitely different than the tests in the College Board's Real SAT II Subject Tests book. You have to create a profile on the website in order to download the tests, but it takes seconds and doesn't require any personal info.</p>

<p>Anyone know where to find other real subject tests, other than those in the CB book? It's lame that CB has only officially released one test per subject.</p>

8

<p>link doesnt work</p>

9

<p><a href="http://bealonghorn.utexas.edu/freshmen/admission/testing/%5B/url%5D"&gt;http://bealonghorn.utexas.edu/freshmen/admission/testing/&lt;/a&gt;&lt;/p>

10

<p>Okay, with regard to your problem M1st3rmarbl3s, you can understand sqrt(x^2) to mean abs(x), as you said. It is exactly the same thing. But C does not work! Look at this: If we take 3, we get abs(3) = 3, but -(3) does not equal 3!</p>

<p>I use trial and error with real numbers to solve these ones. Note that this questions tests your understanding of the fact that the negative of a negative number is a positive number. Its just a logic thing really. Does that answer your question?</p>

11

<p>OOOOOOOOOOOO okay thanks. I lost my 41 neoproto person haha that's the only page i can't find right now. Is it the graph problem? if it is, ummmm something with the negative sign on one formula (i forget) makes it a downwards parabolic function making the only one with a downward parabola the only answer. If this isnt the right one... then ignore what I just said. woot.</p>

12

<p>the sqrt. of x^2 is abs. value of x, hence it can be +x or -X, the answer is d.</p>

13

<p>NO, the answer cannot be D because D includes negative numbers. As I described above, the equation does not work for negative numbers. You end up with a statement like 5=-5 which is clearly incorrect. Use real examples and you will not make mistakes with + / - signs.</p>

14

<p>I guess in these sorts of problems you should try:</p>

<p>a positive number
a negative number
zero....</p>