document.write( "Question 253264: What is the optimal value of this function: y=0.5x^2+2x+3 \n" ); document.write( "
Algebra.Com's Answer #185539 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
I'm assuming that when you say 'optimal', you mean smallest (as in say the lowest cost).\r
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\n" ); document.write( "\n" ); document.write( "Take note that \"y=0.5x%5E2%2B2x%2B3\" is equivalent to \"y=%281%2F2%29x%5E2%2B2x%2B3\" since \"1%2F2=0.5\"\r
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\n" ); document.write( "\n" ); document.write( "To find the optimal value, we need to find the vertex.\r
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\n" ); document.write( "\n" ); document.write( "In order to find the vertex, we first need to find the x-coordinate of the vertex.\r
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\n" ); document.write( "\n" ); document.write( "To find the x-coordinate of the vertex, use this formula: \"x=%28-b%29%2F%282a%29\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-b%29%2F%282a%29\" Start with the given formula.\r
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\n" ); document.write( "\n" ); document.write( "From \"y=%281%2F2%29x%5E2%2B2x%2B3\", we can see that \"a=1%2F2\", \"b=2\", and \"c=3\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-%282%29%29%2F%282%281%2F2%29%29\" Plug in \"a=1%2F2\" and \"b=2\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-2%29%2F%281%29\" Multiply 2 and \"1%2F2\" to get \"1\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=-2\" Divide.\r
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\n" ); document.write( "\n" ); document.write( "So the x-coordinate of the vertex is \"x=-2\". Note: this means that the axis of symmetry is also \"x=-2\".\r
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\n" ); document.write( "\n" ); document.write( "Now that we know the x-coordinate of the vertex, we can use it to find the y-coordinate of the vertex.\r
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\n" ); document.write( "\n" ); document.write( "\"y=%281%2F2%29x%5E2%2B2x%2B3\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"y=%281%2F2%29%28-2%29%5E2%2B2%28-2%29%2B3\" Plug in \"x=-2\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=%281%2F2%29%284%29%2B2%28-2%29%2B3\" Square \"-2\" to get \"4\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=2%2B2%28-2%29%2B3\" Multiply \"1%2F2\" and \"4\" to get \"2\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=2-4%2B3\" Multiply \"2\" and \"-2\" to get \"-4\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=1\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "So the y-coordinate of the vertex is \"y=1\".\r
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\n" ); document.write( "\n" ); document.write( "So the vertex is .\r
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\n" ); document.write( "\n" ); document.write( "Since the max/min occurs at the vertex as the 'y' value, this means that the min is \"y=1\". So the optimal value is is \"y=1\".\r
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\n" ); document.write( "\n" ); document.write( "Here's a graph to visually confirm the answer:\r
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\n" ); document.write( "\n" ); document.write( "Graph of \"y=0.5x%5E2%2B2x%2B3\"
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