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	<title>Comments for Phil Wilson's Mathematics Weblog</title>
	<atom:link href="http://reallyhardsums.wordpress.com/comments/feed/" rel="self" type="application/rss+xml" />
	<link>http://reallyhardsums.wordpress.com</link>
	<description>The eternal comprehensibility of beauty</description>
	<pubDate>Fri, 04 Jul 2008 01:23:31 +0000</pubDate>
	<generator>http://wordpress.org/?v=MU</generator>
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		<title>Comment on Math Forum by Geoff</title>
		<link>http://reallyhardsums.wordpress.com/math-forum/#comment-2735</link>
		<dc:creator>Geoff</dc:creator>
		<pubDate>Sat, 28 Jun 2008 03:02:45 +0000</pubDate>
		<guid isPermaLink="false">http://reallyhardsums.wordpress.com/math-forum/#comment-2735</guid>
		<description>I came across a description of this function years ago (I think in a differential equations textbook) and attempted to solve it on and off for a long time.  This function has the characteristic that the tangent length (between the function and where the tangent line intersects the x-axis) has constant value 1.  Clearly the function has value 1 and infinite slope at x=0 and the function asymptotically approaches zero as x increases to infinity.

I had an insight recently and (with the help of an online integrator function) solved for the function's inverse:
x = -ln(y) + ln(sqrt(1-y^2)+1) - sqrt(1-y^2)
It's an elegant looking broad spike.  


Questions for you:
a) Any ideas on how to invert this to get y in terms of x?
b) Is there a common name or term for this function?

Thanks!</description>
		<content:encoded><![CDATA[<p>I came across a description of this function years ago (I think in a differential equations textbook) and attempted to solve it on and off for a long time.  This function has the characteristic that the tangent length (between the function and where the tangent line intersects the x-axis) has constant value 1.  Clearly the function has value 1 and infinite slope at x=0 and the function asymptotically approaches zero as x increases to infinity.</p>
<p>I had an insight recently and (with the help of an online integrator function) solved for the function&#8217;s inverse:<br />
x = -ln(y) + ln(sqrt(1-y^2)+1) - sqrt(1-y^2)<br />
It&#8217;s an elegant looking broad spike.  </p>
<p>Questions for you:<br />
a) Any ideas on how to invert this to get y in terms of x?<br />
b) Is there a common name or term for this function?</p>
<p>Thanks!</p>
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		<title>Comment on Math Forum by zajoman</title>
		<link>http://reallyhardsums.wordpress.com/math-forum/#comment-2734</link>
		<dc:creator>zajoman</dc:creator>
		<pubDate>Fri, 27 Jun 2008 20:38:23 +0000</pubDate>
		<guid isPermaLink="false">http://reallyhardsums.wordpress.com/math-forum/#comment-2734</guid>
		<description>Please, if you would be so kind, leave me a post on that forum. Thank you.</description>
		<content:encoded><![CDATA[<p>Please, if you would be so kind, leave me a post on that forum. Thank you.</p>
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		<title>Comment on Math Forum by zajoman</title>
		<link>http://reallyhardsums.wordpress.com/math-forum/#comment-2733</link>
		<dc:creator>zajoman</dc:creator>
		<pubDate>Fri, 27 Jun 2008 20:35:50 +0000</pubDate>
		<guid isPermaLink="false">http://reallyhardsums.wordpress.com/math-forum/#comment-2733</guid>
		<description>My friend and I have been puzzled by how to calculate a working fight system for a game with given rules. Here is the problem: http://www.gamedev.net/community/forums/topic.asp?topic_id=499364</description>
		<content:encoded><![CDATA[<p>My friend and I have been puzzled by how to calculate a working fight system for a game with given rules. Here is the problem: <a href="http://www.gamedev.net/community/forums/topic.asp?topic_id=499364" rel="nofollow">http://www.gamedev.net/community/forums/topic.asp?topic_id=499364</a></p>
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		<title>Comment on Math Forum by kyle</title>
		<link>http://reallyhardsums.wordpress.com/math-forum/#comment-2727</link>
		<dc:creator>kyle</dc:creator>
		<pubDate>Wed, 25 Jun 2008 00:59:37 +0000</pubDate>
		<guid isPermaLink="false">http://reallyhardsums.wordpress.com/math-forum/#comment-2727</guid>
		<description>it turns out after doing a little research that by "average" i meant "mean".</description>
		<content:encoded><![CDATA[<p>it turns out after doing a little research that by &#8220;average&#8221; i meant &#8220;mean&#8221;.</p>
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		<title>Comment on Math Forum by kyle</title>
		<link>http://reallyhardsums.wordpress.com/math-forum/#comment-2726</link>
		<dc:creator>kyle</dc:creator>
		<pubDate>Tue, 24 Jun 2008 23:17:52 +0000</pubDate>
		<guid isPermaLink="false">http://reallyhardsums.wordpress.com/math-forum/#comment-2726</guid>
		<description>i'm not sure. when all hourly rates from 1st thru 10th are added up then the toal divided 10 (the number of employees). that number should equal $8.50/hr. been a while since i've taken any math but i always thought that was called the average?</description>
		<content:encoded><![CDATA[<p>i&#8217;m not sure. when all hourly rates from 1st thru 10th are added up then the toal divided 10 (the number of employees). that number should equal $8.50/hr. been a while since i&#8217;ve taken any math but i always thought that was called the average?</p>
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		<title>Comment on Math Forum by Phil Wilson</title>
		<link>http://reallyhardsums.wordpress.com/math-forum/#comment-2725</link>
		<dc:creator>Phil Wilson</dc:creator>
		<pubDate>Tue, 24 Jun 2008 22:30:28 +0000</pubDate>
		<guid isPermaLink="false">http://reallyhardsums.wordpress.com/math-forum/#comment-2725</guid>
		<description>Kyle, it depends what you mean by "average": the mean, the mode, the median?</description>
		<content:encoded><![CDATA[<p>Kyle, it depends what you mean by &#8220;average&#8221;: the mean, the mode, the median?</p>
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		<title>Comment on Math Forum by kyle</title>
		<link>http://reallyhardsums.wordpress.com/math-forum/#comment-2724</link>
		<dc:creator>kyle</dc:creator>
		<pubDate>Tue, 24 Jun 2008 21:00:12 +0000</pubDate>
		<guid isPermaLink="false">http://reallyhardsums.wordpress.com/math-forum/#comment-2724</guid>
		<description>A performance based company pays its best employee top pay. (M=$15.00/hr) And it's worst employee the lowest rate. (m=$6.00/hr) The company is shooting for an average pay rate each week. (A = $8.50/hr) The number of employees can change week to week, we'll assume 10 for this week. (E=10)

how do you figure how much to give second place and third and so on down to 10th place.

1. $15.00/hr
2. ?
3. ?
4. ?
5. ?
6. ?
7. ?
8. ?
9. ?
10. $6.00/hr

i think variance is the key but all the examples i see ask for the data set first. also i don't know how to adjust for the $8.50/hr average.

thanks</description>
		<content:encoded><![CDATA[<p>A performance based company pays its best employee top pay. (M=$15.00/hr) And it&#8217;s worst employee the lowest rate. (m=$6.00/hr) The company is shooting for an average pay rate each week. (A = $8.50/hr) The number of employees can change week to week, we&#8217;ll assume 10 for this week. (E=10)</p>
<p>how do you figure how much to give second place and third and so on down to 10th place.</p>
<p>1. $15.00/hr<br />
2. ?<br />
3. ?<br />
4. ?<br />
5. ?<br />
6. ?<br />
7. ?<br />
8. ?<br />
9. ?<br />
10. $6.00/hr</p>
<p>i think variance is the key but all the examples i see ask for the data set first. also i don&#8217;t know how to adjust for the $8.50/hr average.</p>
<p>thanks</p>
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		<title>Comment on Math Forum by Phil Wilson</title>
		<link>http://reallyhardsums.wordpress.com/math-forum/#comment-2720</link>
		<dc:creator>Phil Wilson</dc:creator>
		<pubDate>Mon, 23 Jun 2008 22:46:22 +0000</pubDate>
		<guid isPermaLink="false">http://reallyhardsums.wordpress.com/math-forum/#comment-2720</guid>
		<description>Hi Greg, and thanks for your long and interesting question. I'm sorry about this, but the blog is hibernating, as you may have noticed, and I don't think I have the time to answer your question with the care it deserves.

Good luck!</description>
		<content:encoded><![CDATA[<p>Hi Greg, and thanks for your long and interesting question. I&#8217;m sorry about this, but the blog is hibernating, as you may have noticed, and I don&#8217;t think I have the time to answer your question with the care it deserves.</p>
<p>Good luck!</p>
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		<title>Comment on Math Forum by Greg</title>
		<link>http://reallyhardsums.wordpress.com/math-forum/#comment-2707</link>
		<dc:creator>Greg</dc:creator>
		<pubDate>Thu, 19 Jun 2008 14:37:43 +0000</pubDate>
		<guid isPermaLink="false">http://reallyhardsums.wordpress.com/math-forum/#comment-2707</guid>
		<description>I have two charts. One chart has the likelihood that a musical pitch will occur in "good" western melodies. Each is weighted with a number. In the key of C Major the notes are weighted like this;

C=5, D=3.5, E=2, F=4, G=4.5, A=3.5, B=4.

I have another chart with the frequency of intervals that occur within "good" western melodies. They are weighted like this;

Unison=5 (the next note is the same as the previous note)
Minor Second=5.5
Major Second=15
Minor Third=2.5
Major Third=2
Perfect Fourth=3
Tritone=0
Perfect Fifth=1.5
Minor Sixth=.125
Major Sixth=.25
Minor Seventh=.25
Major Seventh=.25
Octave=1

I want to combine this data to find out the likelihood of all the possible combinations of motion. I'm looking for the answer to all of the questions below;

What is the likelihood that C will move to D? The answer would be expressed something like C has a 24 chances out of 123 to move to D.
What is the likelihood that C will move to the E above?
what is the likelihood that C will move to the E below?
What is the likelihood that Middle C will move to F above? to the F below? to G above? to G below? to A above? to A below? to B above, to B below? to the octave above to the octave below?

but we're not finished.

What is the likelihood that D will move to the C below?
What is the likelihood that will will move to the C above? 
What is the likelihood that D will stay on D?
What is the likelihood that D will move to E above? to the E below?
to F above, to the F below? to G above, to the G below? to A above, to the A below, to B above, to B below?

still not finished.

What is the likelihood that E will move to C the below? to the C above?
What is the likelihood that E will move to D above? to D below?
What is the likelihood that E will stay on E? Move to F above? F below? G above? G below, A above? A below? B above? B below? Octave above? Octave below? 

Etc...

The difficulty I'm having with the question is correctly graphing the problem. I've tried several times and each time I notice something I missed before in order to get the right answer. Especially confusing to me is the Frequency of notes graph. I thought I could put the name of the pitches on the left hand side of the page with D above at the bottom since the Major second was the most important interval then mark up lines on the graph paper the appropriate number (15). 
Then at the top of that write the word Unison since that is the second most important interval continuing on up in that manner. On the right hand  side of the page I wrote C on the bottom across from the first item in the other graph. Then I counted up the appropriate number of lines. then wrote the next two common pitches E and G. continuing up like that. 
Then I drew a line between C the pitch to the unison interval in the other graph looking for the point in-between that would show the likelihood that the pitch would stay on the same pitch based on what pitch your on in a melody? What I want to know is when I'm looking at the melody I'm writing and I'm in the middle of writing it and, for example, I'm on the note D, then what is the likelihood that D will move to any other note?
 It has the greatest chance of going back to C since D is a less important pitch and since the motion of the Major Second is more important than the motion repeating it again. But I want to know the exact percentage of every possibility. 

Tall order. I know. But it's fun and interesting.</description>
		<content:encoded><![CDATA[<p>I have two charts. One chart has the likelihood that a musical pitch will occur in &#8220;good&#8221; western melodies. Each is weighted with a number. In the key of C Major the notes are weighted like this;</p>
<p>C=5, D=3.5, E=2, F=4, G=4.5, A=3.5, B=4.</p>
<p>I have another chart with the frequency of intervals that occur within &#8220;good&#8221; western melodies. They are weighted like this;</p>
<p>Unison=5 (the next note is the same as the previous note)<br />
Minor Second=5.5<br />
Major Second=15<br />
Minor Third=2.5<br />
Major Third=2<br />
Perfect Fourth=3<br />
Tritone=0<br />
Perfect Fifth=1.5<br />
Minor Sixth=.125<br />
Major Sixth=.25<br />
Minor Seventh=.25<br />
Major Seventh=.25<br />
Octave=1</p>
<p>I want to combine this data to find out the likelihood of all the possible combinations of motion. I&#8217;m looking for the answer to all of the questions below;</p>
<p>What is the likelihood that C will move to D? The answer would be expressed something like C has a 24 chances out of 123 to move to D.<br />
What is the likelihood that C will move to the E above?<br />
what is the likelihood that C will move to the E below?<br />
What is the likelihood that Middle C will move to F above? to the F below? to G above? to G below? to A above? to A below? to B above, to B below? to the octave above to the octave below?</p>
<p>but we&#8217;re not finished.</p>
<p>What is the likelihood that D will move to the C below?<br />
What is the likelihood that will will move to the C above?<br />
What is the likelihood that D will stay on D?<br />
What is the likelihood that D will move to E above? to the E below?<br />
to F above, to the F below? to G above, to the G below? to A above, to the A below, to B above, to B below?</p>
<p>still not finished.</p>
<p>What is the likelihood that E will move to C the below? to the C above?<br />
What is the likelihood that E will move to D above? to D below?<br />
What is the likelihood that E will stay on E? Move to F above? F below? G above? G below, A above? A below? B above? B below? Octave above? Octave below? </p>
<p>Etc&#8230;</p>
<p>The difficulty I&#8217;m having with the question is correctly graphing the problem. I&#8217;ve tried several times and each time I notice something I missed before in order to get the right answer. Especially confusing to me is the Frequency of notes graph. I thought I could put the name of the pitches on the left hand side of the page with D above at the bottom since the Major second was the most important interval then mark up lines on the graph paper the appropriate number (15).<br />
Then at the top of that write the word Unison since that is the second most important interval continuing on up in that manner. On the right hand  side of the page I wrote C on the bottom across from the first item in the other graph. Then I counted up the appropriate number of lines. then wrote the next two common pitches E and G. continuing up like that.<br />
Then I drew a line between C the pitch to the unison interval in the other graph looking for the point in-between that would show the likelihood that the pitch would stay on the same pitch based on what pitch your on in a melody? What I want to know is when I&#8217;m looking at the melody I&#8217;m writing and I&#8217;m in the middle of writing it and, for example, I&#8217;m on the note D, then what is the likelihood that D will move to any other note?<br />
 It has the greatest chance of going back to C since D is a less important pitch and since the motion of the Major Second is more important than the motion repeating it again. But I want to know the exact percentage of every possibility. </p>
<p>Tall order. I know. But it&#8217;s fun and interesting.</p>
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		<title>Comment on Philosophy of teaching by JAC Courage</title>
		<link>http://reallyhardsums.wordpress.com/2008/03/18/131/#comment-2690</link>
		<dc:creator>JAC Courage</dc:creator>
		<pubDate>Fri, 13 Jun 2008 12:06:31 +0000</pubDate>
		<guid isPermaLink="false">http://reallyhardsums.wordpress.com/2008/03/18/131/#comment-2690</guid>
		<description>kindly copy mails of teaching philosophy to me</description>
		<content:encoded><![CDATA[<p>kindly copy mails of teaching philosophy to me</p>
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