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You can put this solution on YOUR website!
prove that |A•i|² + |A•j|² + |A•k|² = |A|²
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document.write( "The left side = |A•i|² + |A•j|² + |A•k|² = |A|²\r\n" );
document.write( "The right side = |A|²\r\n" );
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document.write( "Let any vector A = < p,q,r >\r\n" );
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document.write( "|A•i|² = |< p,q,r >•< 1,0,0 >|² = |(p)(1)+(q)(0)+(r)(0)|² = |p|² = p²\r\n" );
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document.write( "|A•j|² = |< p,q,r >•< 0,1,0 >|² = |(p)(0)+(q)(1)+(r)(0)|² = |q|² = q²\r\n" );
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document.write( "|A•k|² = |< p,q,r >•< 0,0,1 >|² = |(p)(0)+(q)(0)+(r)(1)|² = |r|² = r²\r\n" );
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document.write( "So the left side = |A•i|² + |A•j|² + |A*k|² = p² + q² + r²\r\n" );
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document.write( "The right side = |A|² = |√p² + q² + r²|² = p² + q² + r²\r\n" );
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document.write( "Edwin \n" );
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