SAT 1 math problem need help

Test Preparation
1

<p>hello I was doing a practice test from 'cracking the SAT" 2007 edition</p>

<p>and I found one of the math problem really weird</p>

<p>it from pg 515 number10,</p>

<p>the question is:</p>

<p>what is the domain of g(x)=square root of x^2-9
A)x>-9
B)x>-3
C)lxl <3
D)lxl >3
E) All real numbers</p>

<p>shouldn't the answer be D?</p>

<p>since x^2-9 should be greater or equal to 0?</p>

<p>the book says the asnwer is E. weird! </p>

<p>any comments?</p>

2

<p>I think you are almost correct, but +3 and -3 should be included. So the true answer is not listed!</p>

3

<p>oh yes, I acknowledge that.
by the way, are mistakes such as this quite often in practice books?</p>

4

<p>What is the difference between SAT Reasoning Math and SAT II Math Level 1?</p>

5

<p>SAT II Math level 1 has precalculus if I recall.</p>