document.write( "Question 103996: Hello, \r
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\n" ); document.write( "\n" ); document.write( "I need help finding the equation of the axis of symmetry and the coordinates of the vertex of the graph of: y=2x^2+4x-5\r
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Algebra.Com's Answer #75668 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
To find the axis of symmetry, use this formula:\r
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\n" ); document.write( "\n" ); document.write( "\"x=-b%2F%282a%29\"\r
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\n" ); document.write( "\n" ); document.write( "From the equation \"y=2x%5E2%2B4x-5\" we can see that a=2 and b=4\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-4%29%2F%282%2A2%29\" Plug in b=4 and a=2\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-4%29%2F4\" Multiply 2 and 2 to get 4\r
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\n" ); document.write( "\n" ); document.write( "\"x=-1\" Reduce\r
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\n" ); document.write( "\n" ); document.write( "So the axis of symmetry is \"x=-1\"\r
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\n" ); document.write( "\n" ); document.write( "So the x-coordinate of the vertex is \"x=-1\". Lets plug this into the equation to find the y-coordinate of the vertex.\r
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\n" ); document.write( "\n" ); document.write( "Lets evaluate \"f%28-1%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"f%28x%29=2x%5E2%2B4x-5\" Start with the given polynomial\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-1%29=2%28-1%29%5E2%2B4%28-1%29-5\" Plug in \"x=-1\"\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-1%29=2%281%29%2B4%28-1%29-5\" Raise -1 to the second power to get 1\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-1%29=2%2B4%28-1%29-5\" Multiply 2 by 1 to get 2\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-1%29=2%2B-4-5\" Multiply 4 by -1 to get -4\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-1%29=-7\" Now combine like terms\r
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\n" ); document.write( "\n" ); document.write( "So the vertex is (-1,-7)\r
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\n" ); document.write( "\n" ); document.write( "Notice if you graph the equation \"y=2x%5E2%2B4x-5\" you get\r
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\n" ); document.write( "\n" ); document.write( "and you can see that the vertex is (-1,-7)\r
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