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May 06, 2025, 01:44:11 pm
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Author Topic: inequalities  (Read 1036 times)  Share 

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lisafaustina

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inequalities
« on: October 08, 2010, 08:18:07 pm »
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when do we swap the inequality sign?
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ilovecake

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Re: inequalities
« Reply #1 on: October 08, 2010, 08:20:16 pm »
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When you multiply or divide by a negative number I believe.
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8039

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Re: inequalities
« Reply #2 on: October 08, 2010, 08:37:54 pm »
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Sometimes when finding solutions for quadratic inequalities I think you have to graph the parabola and through observation decide which which on of your values is greater or less than then intersection point.
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Hutchoo

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Re: inequalities
« Reply #3 on: October 08, 2010, 08:47:56 pm »
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When you have two negatives on either side.

And also:
http://vcenotes.com/forum/index.php/topic,27844.msg297887.html#msg297887 -> If you needed an example.
« Last Edit: October 08, 2010, 08:51:17 pm by Hutchoo »
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/0

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Re: inequalities
« Reply #4 on: October 09, 2010, 01:44:52 am »
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If both sides have the same sign and you reciprocate them
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roberto

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Re: inequalities
« Reply #5 on: October 09, 2010, 02:19:01 am »
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i think theres a whole list of rules for different topics but the main ones are when u neg both sides or u flip both sides
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kriptik

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Re: inequalities
« Reply #6 on: October 09, 2010, 09:23:25 am »
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when you do logarithms with numbers less than 1 you change the direction also

(might be useful in some binomial distribution questions)

eg:




« Last Edit: October 09, 2010, 09:26:09 am by kriptik »
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lisafaustina

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Re: inequalities
« Reply #7 on: October 09, 2010, 07:59:00 pm »
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when you have something like
xln(2) > ln(3)
does that become
x<ln(3)/ln(2)
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TrueTears

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Re: inequalities
« Reply #8 on: October 09, 2010, 08:05:32 pm »
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Good notes on inequalities, take a read.
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Blakhitman

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Re: inequalities
« Reply #9 on: October 09, 2010, 08:32:50 pm »
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Quote from: lisafaustina on October 09, 2010, 07:59:00 pm
when you have something like
xln(2) > ln(3)
does that become
x<ln(3)/ln(2)

It's only when the argument (in the log) is less than 1 because then it is a negative value and thus dividing by negative you switch the sign.
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stonecold

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Re: inequalities
« Reply #10 on: October 09, 2010, 08:42:21 pm »
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Quote from: 8039 on October 08, 2010, 08:37:54 pm
Sometimes when finding solutions for quadratic inequalities I think you have to graph the parabola and through observation decide which which on of your values is greater or less than then intersection point.

This is the easiest way...
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Martoman

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Re: inequalities
« Reply #11 on: October 10, 2010, 12:38:43 am »
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Quote from: TrueTears on October 09, 2010, 08:05:32 pm
Good notes on inequalities, take a read.

Wow as if we haven't been taught this formally in school!?!? I like these notes. Can more be found on other topics on the forum?
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Hutchoo

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Re: inequalities
« Reply #12 on: October 10, 2010, 01:12:54 am »
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Quote from: Martoman on October 10, 2010, 12:38:43 am
Quote from: TrueTears on October 09, 2010, 08:05:32 pm
Good notes on inequalities, take a read.

Wow as if we haven't been taught this formally in school!?!? I like these notes. Can more be found on other topics on the forum?

They're beast! I WANT SOME MORE!
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