document.write( "Question 1002047: The sum of the lengths of the two perpendicular sides of a right triangle is 30 centimeters. What are their lengths if the square of the hypotenuse is a minimum? \n" ); document.write( "
Algebra.Com's Answer #619078 by MathTherapy(10552)\"\" \"About 
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The sum of the lengths of the two perpendicular sides of a right triangle is 30 centimeters. What are their lengths if the square of the hypotenuse is a minimum?
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The square of the hypotenuse is the sum of the squares of the legs
\n" ); document.write( "Therefore, their sum is 30, and the hypotenuse (SUM OF THEIR SQUARES) is a minimum (you may recall that: \"a%5E2+%2B+b%5E2+=+c%5E2\")\r
\n" ); document.write( "\n" ); document.write( "Let longer leg be x, and shorter, y
\n" ); document.write( "Then we have: x + y = 30______y = - x + 30 ------- eq (i)
\n" ); document.write( "Also, \"y+=+x%5E2+%2B+y%5E2\" -------- eq (ii)
\n" ); document.write( "\"y+=+x%5E2+%2B+%28-+x+%2B+30%29%5E2\" ------- Substituting - x + 30 for y in eq (ii)
\n" ); document.write( "\"y+=+x%5E2+%2B+x%5E2+-+60x+%2B+900+\"
\n" ); document.write( "\"y+=+2x%5E2+-+60x+%2B+900\"\r
\n" ); document.write( "\n" ); document.write( "MINIMUM occurs at: x = \"-+b%2F%282a%29\", or at: \"x+=+-+-+60%2F%282+%2A+2%29\", or at \"x+=+60%2F4\", or at: x = 15
\n" ); document.write( "With MINIMUM occurring at x = 15, we get:
\n" ); document.write( "y = - 15 + 30 ----------- Substituting 15 for x in eq (i)
\n" ); document.write( "y = 15
\n" ); document.write( "Thus, length of each leg is: \"highlight_green%2815%29\" cm \n" ); document.write( "
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