PR Math Grid In Help.

Test Preparation SAT Preparation
1

<p>Ok. I just took a diagnostic test for my PR course. I will get my scores back next week. But I have a question about one of their math grid-ins.</p>

<p>There is a graph of a “S” shaped function hitting the origin, and nothing can be estimated accurately according to the graph.</p>

<li>On the graph above, for how many values of x does y=x?</li>
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<p>[I put 3 for the wrong reason.] Can someone explain the correct answer?</p>

2

<p>Well, without seeing the problem or graph, I can tell you that it’s the number of values when the graph is in QI or QIII. That is when both x and y values are either positive or negative.</p>

<p>When the graph is in QII or QIV, the x and y values could be the same but they would be opposite signs.</p>

3

<p>But the “S” extends for quite some distance. How would you know that y=x at most 1 point in QI and QIII.</p>

4

<p>Where does it extend to/from? If it extends from QII, goes into QI and QIII, and then extends out the other way in QIV, it is a finite number because the portions of the function in QI and QIII are contained. Do you see what I mean, in that it doesn’t matter if they exist on forever out into QII and QIV? It’s only what’s in QI and QIII that counts.</p>

5

<p>It’s a regular “S” that touches the origin at exactly the middle. The “S” is funny looking and not even symmetric.</p>

6

<p>All you needed to do was superimpose a graph of y=x on top of the s shaped graph to get your answer…</p>

7

<p>Wow crosscurrent. I never though of that! THANKS!</p>