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\vec b | , \text if ( \vec a %2B \vec b ) \cdot ( \vec a - \vec b ) = 8 |
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Answer» Given~|a|=8|b| As we know, |a|=a |b|=b Then we can write a=8b……………(1) And there is,(a+b)(a-b)=8 Solving, a(a-b)+b(a-b)=8 a^2-b^2=8 From 1 (8b)^2-b^2=8 64b^2-b^2=8 63b^2=8 b=8/63hencea=8*8/63=64/63 |
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