document.write( "Question 31878: for the function y=x2-4x-5, perform the following tasks:
\n" ); document.write( "a) Put the function in the form y=a(x-h)2 +k ....the 2 after x is x squared, and the 2 after h is (x-h)squared
\n" ); document.write( "b)what is the line of symmetry?
\n" ); document.write( "c) Graph the function using the equation in part a. Explain why it is not necessary to plot points to graph when using y=a(x-h)2 +k (the 2 after (x-h) is squared
\n" ); document.write( "d) how does this graph compare to the graph of y=x2(xsquared)
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Algebra.Com's Answer #18479 by longjonsilver(2297)\"\" \"About 
You can put this solution on YOUR website!
\"+y=x%5E2-4x-5+\"\r
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\n" ); document.write( "\n" ); document.write( "2a=-4
\n" ); document.write( "--> a = -2
\n" ); document.write( "and so \"a%5E2+=+4\"\r
\n" ); document.write( "\n" ); document.write( "\"+y=x%5E2-4x%28%2B4-4%29-5+\" --> the +4-4 is zero, so we haven't actually altered the equation.\r
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\n" ); document.write( "\n" ); document.write( "\"+y=%28x%5E2-4x%2B4%29-4-5+\"
\n" ); document.write( "\"+y=%28x-2%29%5E2-4-5+\"
\n" ); document.write( "\"+y=%28x-2%29%5E2-9+\"
\n" ); document.write( "\"+y=%28x-2%29%5E2%2B%28-9%29+\" which is now of the form required.\r
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\n" ); document.write( "\n" ); document.write( "b. Line of symmetry is x=2\r
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\n" ); document.write( "\n" ); document.write( "c. We know the apex of the curve...it is (2,-9) and the \"x%5E2\" term is positive, meaning it is u-shaped rather than n-shaped. So we get \"+graph%28300%2C300%2C-4%2C8%2C-10%2C4%2Cx%5E2-4x-5%29+\". However, purely looking at the equation in this form does not \"instantly\" tell us the intercepts on the axes... some algebra, minimal yes, is still required.\r
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\n" ); document.write( "\n" ); document.write( "d. \"y=x%5E2\" moved by 2 units to the right gives \"y=%28x-2%29%5E2\" and then this moved by 9 units down is given by \"y=%28x-2%29%5E2+-+9\"\r
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\n" ); document.write( "\n" ); document.write( "Here are all 3 stages: \"y=x%5E2\", \"y=%28x-2%29%5E2\" and \"y=%28x-2%29%5E2-9\" on the same scales, so you can see them:\r
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\n" ); document.write( "\n" ); document.write( "\"+graph%28300%2C300%2C-4%2C8%2C-10%2C20%2Cx%5E2%29+\"
\n" ); document.write( "\"+graph%28300%2C300%2C-4%2C8%2C-10%2C20%2C%28x-2%29%5E2%29+\"
\n" ); document.write( "\"+graph%28300%2C300%2C-4%2C8%2C-10%2C20%2C%28x-2%29%5E2-9%29+\"\r
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\n" ); document.write( "\n" ); document.write( "jon.
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