document.write( "Question 663417: Hello, this question loses me, I tried setting this up in a y=x^2+z^2 format and substituting but I get lost very quickly.\r
\n" ); document.write( "\n" ); document.write( "QUESTION: \"Find two non-negative numbers whose sum is 18.5 and the sum of their squares is a minimum.\"\r
\n" ); document.write( "\n" ); document.write( "I had
\n" ); document.write( "x^2+(18.5-x)^2
\n" ); document.write( "=x^2+342.25-37x+x^2
\n" ); document.write( "=2x^2-37x+342.25
\n" ); document.write( "and then I got very lost. Someone suggested I used -b/2a to help me solve but I'm not sure what I'm supposed to do.\r
\n" ); document.write( "\n" ); document.write( "Thanks for the help in advance!
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Algebra.Com's Answer #412793 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
Suppose I vary one of the numbers and hold
\n" ); document.write( "the other number fixed, but not saying
\n" ); document.write( "right away what it is fixed at.
\n" ); document.write( "Let the variable number = \"+x+\"
\n" ); document.write( "Let the fixed number = \"+a+\"
\n" ); document.write( "given:
\n" ); document.write( "\"+x+%2B+a+=+18.5+\"
\n" ); document.write( "\"+f%28x%29+=+x%5E2+%2B+a%5E2+\"
\n" ); document.write( "--------------------
\n" ); document.write( "\"+a+=+18.5+-+x++\"
\n" ); document.write( "\"+f%28x%29+=+x%5E2+%2B+%28+18.5+-+x+%29%5E2+\"
\n" ); document.write( "\"+f%28x%29+=+x%5E2+%2B+342.25+-+37x+%2B+x%5E2+\"
\n" ); document.write( "\"+f%28x%29+=+2x%5E2+-+37x+%2B+342.25+\" ( just what you got )
\n" ); document.write( "-----------------------------
\n" ); document.write( "This is in the form \"+ax%5E2+%2B+bx+%2B+c+\", so the
\n" ); document.write( "minimum is at \"+-b%2F%282a%29+\"
\n" ); document.write( "\"+a+=+2+\"
\n" ); document.write( "\"+b+=+-37+\"
\n" ); document.write( "\"+-b%2F%282a%29+=+-%28-37%29+%2F+%282%2A2%29+\"
\n" ); document.write( "\"+-b%2F%282a%29+=+37%2F4+\"
\n" ); document.write( "\"+37%2F4+=+9.25+\"
\n" ); document.write( "and
\n" ); document.write( "\"+a+=+18.5+-+x++\"
\n" ); document.write( "\"+a+=+18.5+-+9.25+\"
\n" ); document.write( "\"+a+=+9.25+\"
\n" ); document.write( "Both numbers are 9.25
\n" ); document.write( "check:
\n" ); document.write( "\"+2%2A9.25%5E2++=+171.125+\"
\n" ); document.write( "-----------------------
\n" ); document.write( "What if the numbers are
\n" ); document.write( "9.24 and 9.26
\n" ); document.write( "\"+9.24%5E2+%2B+9.26%5E2+=+85.3776+%2B+85.7476+\"
\n" ); document.write( "\"+85.3776+%2B+85.7476+=+171.1252+\"
\n" ); document.write( "This is higher than \"+2%2A9.25%5E2+\"
\n" ); document.write( "So we have a minimum
\n" ); document.write( " \r
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