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Topic: ONE REAL SOLUTION (Read 606 times) |
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karan
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ONE REAL SOLUTION
« on: Sep 4th, 2008, 3:15am » |
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18 = ((1 + x)^18/x)
17 = ((1 + x)^17/x)
Subtract => 1=1+x but x can't be zero
Hence, no soln. (the soln. given in the problem is also incorrect)
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towr
wu::riddles Moderator
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Re: ONE REAL SOLUTION
« Reply #1 on: Sep 4th, 2008, 6:04am » |
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How do you come by 1=1+x?
((1 + x)^18/x) = (1 + x) (1 + x)^17/x
So, subtracting the second equation from the first yield
1 = (1 + x)^17
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karan
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Re: ONE REAL SOLUTION
« Reply #2 on: Sep 4th, 2008, 8:07am » |
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same thing, 1=(1+x)^17 is same as 1=1+x
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Grimbal
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Re: ONE REAL SOLUTION
« Reply #3 on: Sep 4th, 2008, 9:51am » |
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Anyway, plotting the function ((1+x)^18)/x shows a minimum of 47.56 at x=1/17.
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| « Last Edit: Sep 4th, 2008, 9:52am by Grimbal » |
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teekyman
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Re: ONE REAL SOLUTION
« Reply #4 on: Sep 4th, 2008, 12:11pm » |
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You can also divide one by the other to get 18/17 = 1+x, a contradiction.
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