document.write( "Question 40291: Australian football is played on an elliptical field. The official rules state that the field must be between 135 and 185 meters long and between 110 and 155 meters wide.\r
\n" ); document.write( "\n" ); document.write( "a) write an equation for the largest allowable playing field.
\n" ); document.write( "b) write an equation for the smallest allowable playing field.
\n" ); document.write( "c) write an inequality that describes the possible areas of an Australian football field.
\n" ); document.write( "

Algebra.Com's Answer #25646 by AnlytcPhil(1806)\"\" \"About 
You can put this solution on YOUR website!
Australian football is played on an elliptical field. The official rules state\r\n" );
document.write( "that the field must be between 135 and 185 meters long and between 110 and 155\r\n" );
document.write( "meters wide.\r\n" );
document.write( "\r\n" );
document.write( "a = semi-major axis's length\r\n" );
document.write( "2a = major axis's length = length of field\r\n" );
document.write( "\r\n" );
document.write( ">>...the field must be between 135 and 185 meters long...<<\r\n" );
document.write( "\r\n" );
document.write( "                135 < 2a < 185\r\n" );
document.write( "\r\n" );
document.write( "Divide through by 2\r\n" );
document.write( "\r\n" );
document.write( "               67.5 < a < 92.5 \r\n" );
document.write( "\r\n" );
document.write( "b = semi-minor axis's length\r\n" );
document.write( "2b = minor axis's width = width of field\r\n" );
document.write( "\r\n" );
document.write( ">>...the field must be...between 110 and 155 meters wide...<<\r\n" );
document.write( "\r\n" );
document.write( "                110 < 2b < 155\r\n" );
document.write( "\r\n" );
document.write( "Divide through by 2:\r\n" );
document.write( "\r\n" );
document.write( "                 55 < b < 77.5 \r\n" );
document.write( "\r\n" );
document.write( " \r\n" );
document.write( "a) write an equation for the largest allowable playing field.\r\n" );
document.write( "\r\n" );
document.write( "The formula for the area of an ellipse is \r\n" );
document.write( "\r\n" );
document.write( "                   Area = pab \r\n" );
document.write( "\r\n" );
document.write( "The area is latgest when a and b are the largest, that is when\r\n" );
document.write( "\r\n" );
document.write( "              a = 92.5 and b = 77.5 \r\n" );
document.write( "\r\n" );
document.write( "          Largest area = p(92.5)(77.5)\r\n" );
document.write( "\r\n" );
document.write( "                       = 22521.3 mē approximately. \r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "b) write an equation for the smallest allowable playing field.\r\n" );
document.write( "\r\n" );
document.write( "The area is smallest when a and b are the smallest, that is when\r\n" );
document.write( "\r\n" );
document.write( "              a = 67.5 and b = 55 \r\n" );
document.write( "\r\n" );
document.write( "         Smallest area = p(67.5)(55)\r\n" );
document.write( "        \r\n" );
document.write( "                       = 11663.2 mē approximately.\r\n" );
document.write( "\r\n" );
document.write( "c) write an inequality that describes the possible areas of an Australian\r\n" );
document.write( "football field.\r\n" );
document.write( "\r\n" );
document.write( "                 11663.2 mē < Area <  22521.3 mē\r\n" );
document.write( "\r\n" );
document.write( "Edwin\r\n" );
document.write( "AnlytcPhil@aol.com
\n" ); document.write( "
\n" );