document.write( "Question 77301: I did the problem.. and i want to know if I'm correct! \r
\n" ); document.write( "\n" ); document.write( "Use the quadratic form of completing the square to find the vertex of the following.. f (x) -x^2-6x-5\r
\n" ); document.write( "\n" ); document.write( "Factor out the (-): -(x^2 + 6x + 5)
\n" ); document.write( "B: 6/2(1) = 3
\n" ); document.write( "-(x+3)^2 -9-5
\n" ); document.write( "-(x+3)^2 - 14\r
\n" ); document.write( "\n" ); document.write( "Vertex is.. (-3,-14)\r
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Algebra.Com's Answer #55394 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Factor out -1\r
\n" ); document.write( "\n" ); document.write( "\"-%28x%5E2+%2B+6x+%2B+5%29\"\r
\n" ); document.write( "\n" ); document.write( "Complete the square of the quadratic in the parenthesis\r
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Solved by pluggable solver: Completing the Square to Get a Quadratic into Vertex Form

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\n" ); document.write( " \"y=1+x%5E2%2B6+x%2B5\" Start with the given equation
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\n" ); document.write( " \"y-5=1+x%5E2%2B6+x\" Subtract \"5\" from both sides
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\n" ); document.write( " \"y-5=1%28x%5E2%2B6x%29\" Factor out the leading coefficient \"1\"
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\n" ); document.write( " Take half of the x coefficient \"6\" to get \"3\" (ie \"%281%2F2%29%286%29=3\").
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\n" ); document.write( " Now square \"3\" to get \"9\" (ie \"%283%29%5E2=%283%29%283%29=9\")
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\n" ); document.write( " \"y-5=1%28x%5E2%2B6x%2B9-9%29\" Now add and subtract this value inside the parenthesis. Doing both the addition and subtraction of \"9\" does not change the equation
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\n" ); document.write( " \"y-5=1%28%28x%2B3%29%5E2-9%29\" Now factor \"x%5E2%2B6x%2B9\" to get \"%28x%2B3%29%5E2\"
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\n" ); document.write( " \"y-5=1%28x%2B3%29%5E2-1%289%29\" Distribute
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\n" ); document.write( " \"y-5=1%28x%2B3%29%5E2-9\" Multiply
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\n" ); document.write( " \"y=1%28x%2B3%29%5E2-9%2B5\" Now add \"5\" to both sides to isolate y
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\n" ); document.write( " \"y=1%28x%2B3%29%5E2-4\" Combine like terms
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\n" ); document.write( " Now the quadratic is in vertex form \"y=a%28x-h%29%5E2%2Bk\" where \"a=1\", \"h=-3\", and \"k=-4\". Remember (h,k) is the vertex and \"a\" is the stretch/compression factor.
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\n" ); document.write( " Check:
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\n" ); document.write( " Notice if we graph the original equation \"y=1x%5E2%2B6x%2B5\" we get:
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\n" ); document.write( " \"graph%28500%2C500%2C-10%2C10%2C-10%2C10%2C1x%5E2%2B6x%2B5%29\" Graph of \"y=1x%5E2%2B6x%2B5\". Notice how the vertex is (\"-3\",\"-4\").
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\n" ); document.write( " Notice if we graph the final equation \"y=1%28x%2B3%29%5E2-4\" we get:
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\n" ); document.write( " \"graph%28500%2C500%2C-10%2C10%2C-10%2C10%2C1%28x%2B3%29%5E2-4%29\" Graph of \"y=1%28x%2B3%29%5E2-4\". Notice how the vertex is also (\"-3\",\"-4\").
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\n" ); document.write( " So if these two equations were graphed on the same coordinate plane, one would overlap another perfectly. So this visually verifies our answer.
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\n" ); document.write( "\n" ); document.write( "So the quadratic \"-x%5E2-6x-5\" becomes\r
\n" ); document.write( "\n" ); document.write( "\"-%28%28x%2B3%29%5E2-4%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"-%28x%2B3%29%5E2%2B4%29\"
\n" ); document.write( "Here are the graphs of \"-x%5E2-6x-5\" and \"-%28x%2B3%29%5E2+%2B4\" to verify\r
\n" ); document.write( "\n" ); document.write( "\"+graph%28+300%2C+200%2C+-6%2C+5%2C+-10%2C+10%2C+-x%5E2-6x-5%29+\" graph of \"-x%5E2-6x-5\"\r
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\n" ); document.write( "\n" ); document.write( "\"+graph%28+300%2C+200%2C+-6%2C+5%2C+-10%2C+10%2C+-%28x%2B3%29%5E2+%2B4%29+\" graph of \"-%28x%2B3%29%5E2+%2B4\"\r
\n" ); document.write( "\n" ); document.write( "Vertex: (-3,4)\r
\n" ); document.write( "\n" ); document.write( "Note: you were on the right track but this step
\n" ); document.write( "\"-%28x%2B3%29%5E2+-9-5\"
\n" ); document.write( "should be
\n" ); document.write( "\"-%28x%2B3%29%5E2+%2B9-5=-%28x%2B3%29%5E2%2B4\"
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