Need solutions...

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Labib
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Need solutions...

Unread post by Labib » Thu Dec 16, 2010 12:22 am

Is there any easy method to figure out if there is any solution to an equation like the following one:

$ a^2+b^2=123$

what is the method when the power is a natural number greater than 2(eg 3,4)?
Last edited by Labib on Thu Dec 16, 2010 10:44 pm, edited 1 time in total.
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Labib
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Re: Need solutions...

Unread post by Labib » Thu Dec 16, 2010 12:23 am

ami latex lekhar cheshta korsi. but amar lekha ta latex style e dekhasse na kno?? :'(
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Moon
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Re: Need solutions...

Unread post by Moon » Thu Dec 16, 2010 12:38 am

তুমি এইটাকে বোল্ড করে কালার চেঞ্জ করছ এই কারণে...
a^2+b^2=123$=a^2+b^2=123 $ :)
আর ল্যাটেক চেক করার জন্য টেস্ট ফোরাম ব্যবহার করতে পার।
"Inspiration is needed in geometry, just as much as in poetry." -- Aleksandr Pushkin

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tushar7
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Re: Need solutions...

Unread post by tushar7 » Thu Dec 16, 2010 12:43 am

let $n$ be any integer then ..............
$n^2\equiv 0 or 1 \pmod {4}$
so $a^2+b^2\equiv 2or 0\pmod{4}$
but . $123\equiv 3\pmod{4}$ which contradicts with the original equation .
so there is no solution

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Moon
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Re: Need solutions...

Unread post by Moon » Thu Dec 16, 2010 12:57 am

$a^2+b^2=0,1,2 \pmod{4}$ (you missed $1$)
"Inspiration is needed in geometry, just as much as in poetry." -- Aleksandr Pushkin

Please install LaTeX fonts in your PC for better looking equations,
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tushar7
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Re: Need solutions...

Unread post by tushar7 » Thu Dec 16, 2010 2:51 pm

thanks moon bhaya .i forgot about that , when one can be odd and other one is even

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