\r\n" );
document.write( "We start with this basic squaring function which is \r\n" );
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document.write( "y = x²\r\n" );
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\r\n" );
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document.write( "Now the graph of \r\n" );
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document.write( "(a) y = x² - 4 \r\n" );
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document.write( "looks exactly like the graph of y = x² except that the - 4\r\n" );
document.write( "added on the right shifts the graph down 4 units, and makes\r\n" );
document.write( "the graph drawn in green below:\r\n" );
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\r\n" );
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document.write( "Now the graph of \r\n" );
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document.write( "b) y = -x² \r\n" );
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document.write( "also looks exactly like the graph of y = x² except that multiplying\r\n" );
document.write( "the right side by -1 reflects the graph across the x-axis (as if the\r\n" );
document.write( "x-axis were a mirror; the reflection would be the graph drawn in green \r\n" );
document.write( "below:\r\n" );
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\r\n" );
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document.write( "---\r\n" );
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document.write( "d) y = 5x² \r\n" );
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document.write( "This one is not going to look exactly like the graph of y = x² \r\n" );
document.write( "because multiplying the right side by 5, which is a number greater\r\n" );
document.write( "than 1, is going to stretch the graph vertically. It is the same\r\n" );
document.write( "as if the graph of y=x² had been drawn on a rubber sheet and the \r\n" );
document.write( "rubber sheet stretched 5 times its height. This stretched graph\r\n" );
document.write( "would be the graph drawn in green below:\r\n" );
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document.write( "
\r\n" );
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document.write( "Edwin
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document.write( "![\"\"](\"/images/stars/stars-13.gif\")
