document.write( "Question 1170110: A lamp whose bulb is placed on the focus has a focal diameter of 12 cm.
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Algebra.Com's Answer #795022 by AnlytcPhil(1806) $\"\"$ $\"About$

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document.write( "where (h,k) = (0,0) = the vertex and 4a = focal diameter\r\n" );
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document.write( "The black line is the focal diameter.\r\n" );
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document.write( "We want the length of the red line.\r\n" );
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document.write( "The end points are where y=20\r\n" );
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document.write( "So the red line is twice the absolute value of x.\r\n" );
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document.write( "Answer: , about 30.98\r\n" );
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document.write( "Edwin

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