<p>hey, i'm really confused with a couple of the blue book math questions, and i need some serious help with solving them . . .</p>
<p>PT1 S6 #17 (this one is a grid in)
In the XY-coordinate plane, the graph of x=y^2 -4 intersects line L at (0,p) and (5,t). What is the greatest possible value of the slope of L?</p>
<p>PT3 S8 #9
A regulation for riding a certain amusment park ride requires that a child be between 30 inches and 50 inches tall. Which of the following inequalities can be used to determine whether or not a child's height h satisfies the regulation for this ride?
(A) |h-10| < 50
(B) |h-20| < 40
(C) |h-30| < 20
(D) |h-40| < 10
(E) |h-45| < 5</p>
<p>i'm trying desperately to up my math score for october and really need some help!</p>
<p>If the height range is 30-50, then the child has to be within 10 inches of 40, which is the middle of the range. You need an inequality that says (difference between h to 40) < 10. To find the difference between any number to another number, you subtract them and take the absolute value (because you only want a posiitve difference) to get D: |h-40| < 10</p>
<p>tanman, that's a great example of how ETS protects 800 from smart people.</p>
<p>It's another way around:
0 = p^2-4 --> 2 solutions
5 = t^2-4 --> 2 solutions</p>
<p>There are 2*2=4 possible ways to draw line L, and 4 possible values for its slope.
You don't really need to calculate them all to find the greatest. Think graphically.</p>
<p>What could help you to avoid this mistake?
The words "greatest value". It's extremely unlikely that you asked to find it, but you end up with only one choice.</p>
<p>Whoops.. too early in the morning to be doing SAT problems ;)</p>
<p>Here's a new (hopefully correct) explanation:</p>
<p>0 = p^2-4 => p = 2 or -2 => point A = (0,2) or (0,-2)
5 = t^2-4 => t= 3 or -3 => poing B = (5.3) or (5,-3)</p>
<p>Like gcf101 said, instead of calculating all the slopes, it would probably be easier to plot the four points and look for the pair with the highest (steepest) slope.</p>