<p>I agree ... the answers are so close if you convert into decimal. </p>
<p>Your decimal method gives you a different answer and my fraction method gives a different answer ...
they both seem correct methods, but maybe fractions are more accurate than decimals so maybe 3/4 is the answer.</p>
<p>tbh im confused on what the answer is now.</p>
<p>Umm, I just calculated the answer using all decimal spaces, i.e. 1.33333333333333333333333 and 0.8750000000000000000 and the answer is exactly 0.72727272.....</p>
<p>Lol.</p>
<p>i forget if this question was on Math I or Math II but does anyone remember the sphere into the square question?</p>
<p>Guys, if the answer asked for ALL REAL numbers, it's 8/11. (I don't remember if it did though).
In that case, it doesn't matter if it said greater or equal to or just greater than 1, because there are infinitely many numbers anyway so just one doesn't make a difference.
The number of favorable values lies between 1 and 4/3, so if you subtract you will get 1/3. Think of 1/3 as the "weight" of the favorable values.
The total possible values lies between 7/8 and 4/3. Again, you subtract, and that gives you 11/24.
Then you divide to find the probability of the favorable values, you get 8/11.
I remember doing this type of problem on a past AMC, so I'm pretty sure that this is right.</p>
<p>I did that problem the exact same way 20legend did.
I just looked at my 89, and it has (1/3)/ [(.125+(1/3)]= .7272727272727</p>
<p>And I agree with Procrastination. The question asked for the equation so that if you had f(x)=0, it would still hold true for the same value if you input -x. Obviously, that means either the degrees in all the terms are even with no constant term (so there's symmetry on the x-axis) or they are all odd, given that the only root is zero. Think about it. The other answers all had a melange of odd and even degree terms, and those cannot possibly have the same roots. For example, x^2+2x-1 doesn't have the same roots as (-x)^2-2x-1, now does it?</p>
<p>But 20LEGEND, who's to say that there are only 125 possible choices from 0.875 to 1? It could just as well go from 0.85700001, 0.87500002, 0.87500003......0.9999999, 1.
Kudos for getting the right answer, but I just wanted to point out a flaw in your reasoning.</p>
<p>I stand corrected, Procrastination. I just did it on my TI-89.</p>
<p>The sphere in the square one was Math I, but I forget the exact question.</p>
<p>Aye, what was the answer to the (x-3)(x-4)(x+2)(x+1)<0 question?</p>
<p>qhausqkqh,
when I use 125000000000, that'll take into account values like the ones you mentioned :).</p>
<p>However, Procrastination, are you 100% sure those were the equations? Just because they were in your calculator does not mean you did not type them in wrong. Since I remember putting in -x for x in the x^2 equation and getting the same equation, you may have typed it in wrong. I understand, though, that I may have typed it in wrong, too. So, we're still not sure who's right.</p>
<p>20 Legend, just use a sign analysis: Draw a number line, with the roots, and plug in values in between the roots. The right answer is the one with the - in the interval.</p>
<p>The answer to the F(x) = f(-x), IIRC was something that had a +1 or -1 at the end ..</p>
<p>lewis,
What was it though ?</p>
<p>1<x<2 ?</p>
<p>Thanx, 20LEGEND, that means I am right about the F(x)=-F(-x). But how did you get it?</p>
<p>I'll do your problem now</p>
<p>No, its -2 to -1 and 3 to 4</p>
<p>The question might have been (x+3)(x+4)(x-1)(x-2)<0 btw :S</p>
<p>then its -4 to -3 and 1 to 2. That seems like what I put.</p>
<p>I think it was -2<x<-1</p>
<p>AND 3 to 4</p>