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October 11th, 2009, 06:48 AM
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| |  Complicated Algebra, though I reckon theres a simple answer!
I have been out of eduacation for while so am a bit rusty on my maths, but basically I started with a binomial expansion and have windled it down to the following alebraic equation which i cant seem to simplify anymore!
(n/9)*0.9^n + 0.9^n = 0.5
And obviously im trying to find n, which I know is around 16.5, but only through guessing!
Last edited by mr fantastic; October 11th, 2009 at 09:31 PM.
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October 11th, 2009, 09:30 PM
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Quote:
Originally Posted by ryanhorne  I have been out of eduacation for while so am a bit rusty on my maths, but basically I started with a binomial expansion and have windled it down to the following alebraic equation which i cant seem to simplify anymore!
(n/9)*0.9^n + 0.9^n = 0.5
And obviously im trying to find n, which I know is around 16.5, but only through guessing!
[IMG]file:///C:/DOCUME%7E1/RYAN2%7E1/LOCALS%7E1/Temp/moz-screenshot.png[/IMG][IMG]file:///C:/DOCUME%7E1/RYAN2%7E1/LOCALS%7E1/Temp/moz-screenshot-1.png[/IMG] | An exact answer cannot be obtained using algebraic methods (unless you introduce new functions). Why do you rquire an exact value? And if you don't, then just use technology to solve to required accuracy.
__________________ There are two things you should never try to prove: the impossible and the obvious. The greater danger for most of us lies not in setting our aim too high and falling short; but in setting our aim too low and achieving our mark. (Michelangelo Buonarroti)
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October 12th, 2009, 09:43 AM
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| | I agree
Yes, I do not think a value of n can be obtained from this, as I have spent hours slaving over this! So will have to use Excel.
Cheers for your help |
October 12th, 2009, 10:52 AM
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I don't know how to solve this problem, but I do have mathematica and I think that's a better tool than excel. 
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