\r\n" );
document.write( "\r\n" );
document.write( "I'll do the first and last:\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "Get 0 on one side:\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "To find the critical values set numerator=0,\r\n" );
document.write( "and denominator =0 and solve for x:\r\n" );
document.write( "\r\n" );
document.write( "(2-x)(2+x)=0 gives 2 and -2 as critical values\r\n" );
document.write( "\r\n" );
document.write( "x=0 gives 0 as a critical value.\r\n" );
document.write( "\r\n" );
document.write( "So mark the critical values on a number line:\r\n" );
document.write( "\r\n" );
document.write( "----------o-----o-----o---------\r\n" );
document.write( "-5 -4 -3 -2 -1 0 1 2 3 4 5 \r\n" );
document.write( "\r\n" );
document.write( "First select a test point in the region left\r\n" );
document.write( "of -2. Choose x=-3. Substitute it in\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "That is false, so we do not shade the region\r\n" );
document.write( "left of -2. So we still have the same\r\n" );
document.write( "number line:\r\n" );
document.write( "\r\n" );
document.write( "----------o-----o-----o---------\r\n" );
document.write( "-5 -4 -3 -2 -1 0 1 2 3 4 5 \r\n" );
document.write( "\r\n" );
document.write( "Next select a test point in the region between\r\n" );
document.write( "-2 and 0. Choose x=-1. Substitute it in\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "That is true, so we do shade the region between\r\n" );
document.write( "-2 and 0. So now the number line is\r\n" );
document.write( "\r\n" );
document.write( "----------o=====o-----o---------\r\n" );
document.write( "-5 -4 -3 -2 -1 0 1 2 3 4 5 \r\n" );
document.write( "\r\n" );
document.write( " Next select a test point in the region between\r\n" );
document.write( "0 and 2. Choose x=1. Substitute it in\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "That is false, so we do not shade the region between\r\n" );
document.write( "0 and 2. So the number line is still\r\n" );
document.write( "\r\n" );
document.write( "----------o=====o-----o---------\r\n" );
document.write( "-5 -4 -3 -2 -1 0 1 2 3 4 5\r\n" );
document.write( "\r\n" );
document.write( "finally select a test point in the region right\r\n" );
document.write( "of 2. Choose x=3. Substitute it in\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "That is true, so we do shade the region\r\n" );
document.write( "right of 2. So the final number line is:\r\n" );
document.write( "\r\n" );
document.write( "----------o=====o-----o=========>\r\n" );
document.write( "-5 -4 -3 -2 -1 0 1 2 3 4 5\r\n" );
document.write( "\r\n" );
document.write( "Now we have to test the critical values\r\n" );
document.write( "to see if they are solutions. But that's \r\n" );
document.write( "easy because with strict inequality, none \r\n" );
document.write( "of the critical values can be solutions.\r\n" );
document.write( "\r\n" );
document.write( "In interval notation:\r\n" );
document.write( "\r\n" );
document.write( " (-2,0) U (2,
)\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "Get 0 on one side\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "Get LCD of
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "To find the critical values set numerator=0,\r\n" );
document.write( "and denominator =0 and solve for x:\r\n" );
document.write( "\r\n" );
document.write( "(x-9)(x+2)=0 gives 9 and -2 as critical values\r\n" );
document.write( "\r\n" );
document.write( "2(x+1)=0 gives -1 as a critical value.\r\n" );
document.write( "\r\n" );
document.write( "So mark the critical values on a number line:\r\n" );
document.write( "\r\n" );
document.write( "-------o--o-----------------------------o---------\r\n" );
document.write( "-4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 \r\n" );
document.write( "\r\n" );
document.write( "---\r\n" );
document.write( "First select a test point in the region left\r\n" );
document.write( "of -2. Choose x=-3. Substitute it in\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "That is false, so we do not shade the region\r\n" );
document.write( "left of -2. So we still have the same\r\n" );
document.write( "number line:\r\n" );
document.write( "\r\n" );
document.write( "-------o--o-----------------------------o---------\r\n" );
document.write( "-4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 \r\n" );
document.write( "\r\n" );
document.write( "Next select a test point in the region between\r\n" );
document.write( "-2 and -1. Choose x=-1.5. Substitute it in\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "That is true, so we do shade the region between\r\n" );
document.write( "-2 and -1. So now the number line is\r\n" );
document.write( "\r\n" );
document.write( "-------o==o-----------------------------o---------\r\n" );
document.write( "-4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 \r\n" );
document.write( "\r\n" );
document.write( "Next select a test point in the region between\r\n" );
document.write( "-1 and 9. Choose x=0. Substitute it in\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "That is false, so we do not shade the region\r\n" );
document.write( "between -1 and 9. So we still have the same\r\n" );
document.write( "number line:\r\n" );
document.write( "\r\n" );
document.write( "-------o==o-----------------------------o---------\r\n" );
document.write( "-4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 \r\n" );
document.write( "\r\n" );
document.write( "Finally select a test point in the region right\r\n" );
document.write( "of 9. Choose x=10. Substitute it in\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "That is true, so we do shade the region\r\n" );
document.write( "right of 9. So the number line is now:\r\n" );
document.write( "\r\n" );
document.write( "-------o==o-----------------------------o=========>\r\n" );
document.write( "-4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 \r\n" );
document.write( "\r\n" );
document.write( "Now we have to test the critical values\r\n" );
document.write( "to see if they are solutions. \r\n" );
document.write( "\r\n" );
document.write( "We test critical value -2\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "That is true so we darken the circle at -2, like this:\r\n" );
document.write( "\r\n" );
document.write( "-------@==o-----------------------------o=========>\r\n" );
document.write( "-4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12\r\n" );
document.write( "\r\n" );
document.write( "We test critical value -1\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "This undefined! So we do not darken the circle at -1,\r\n" );
document.write( "but leave it open\r\n" );
document.write( "\r\n" );
document.write( "Now we test critical point x=9\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "That is true so we darken the circle at 9, like this:\r\n" );
document.write( "\r\n" );
document.write( "-------@==o-----------------------------@=========>\r\n" );
document.write( "-4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12\r\n" );
document.write( "\r\n" );
document.write( "The interval notation is:\r\n" );
document.write( "\r\n" );
document.write( " [-2,-1) U [9,
)\r\n" );
document.write( "\r\n" );
document.write( "Edwin
\n" );
document.write( "