document.write( "Question 885961: Please help me prove this equation: 2|x| |y| = x^2 + y^2 \n" ); document.write( "
Algebra.Com's Answer #535607 by rothauserc(4718)\"\" \"About 
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|x| > 0, |y|>0 for all x, y not = 0
\n" ); document.write( "if x = 0 or y = 0 then x = 0 and y = 0, trivial case
\n" ); document.write( "2|x| |y| = x^2 + y^2
\n" ); document.write( "note that |x||y| = |xy|
\n" ); document.write( "2|xy| = x^2 + y^2
\n" ); document.write( "x = y
\n" ); document.write( "2y^2 = y^2 + y^2
\n" ); document.write( "2y^2 = 2y^2
\n" ); document.write( "y^2 = y^2
\n" ); document.write( "y = y
\n" ); document.write( "same process for y = x
\n" ); document.write( " \n" ); document.write( "
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