document.write( "Question 1167274: How do you write equation for this sequence 16, 28, 42, 56 \n" ); document.write( "
Algebra.Com's Answer #792108 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
\r\n" );
document.write( "\r\n" );
document.write( "On your TI calculator,\r\n" );
document.write( "Press STAT\r\n" );
document.write( "Press ENTER\r\n" );
document.write( "Under L1, store 1, 2, 3, 4\r\n" );
document.write( "Under  L2, store 16, 28, 42, 56\r\n" );
document.write( "Press STAT\r\n" );
document.write( "Press the right arrow key to highlight CALC\r\n" );
document.write( "Press 6 for 6:CubicReg\r\n" );
document.write( "See this screen:\r\n" );
document.write( "\r\n" );
document.write( "     CubicReg\r\n" );
document.write( "Xlist:L1\r\n" );
document.write( "Xlist:L2\r\n" );
document.write( "Store RegEQ:\r\n" );
document.write( "Calculate\r\n" );
document.write( "\r\n" );
document.write( "Press down arrow key 4 times to highlight Calculate\r\n" );
document.write( "\r\n" );
document.write( "Press ENTER\r\n" );
document.write( "\r\n" );
document.write( "See this screen:\r\n" );
document.write( "    \r\n" );
document.write( "    CubicReg\r\n" );
document.write( "y=ax3+bx2+cx+d\r\n" );
document.write( "a=-0.333333333\r\n" );
document.write( "b=3\r\n" );
document.write( "c=5.3333333333\r\n" );
document.write( "d=8\r\n" );
document.write( "R2=1\r\n" );
document.write( "\r\n" );
document.write( "Interpret -0.333333333 as -1/3\r\n" );
document.write( "interpret  5.333333333 as 5 1/3 and then as 16/3\r\n" );
document.write( "\r\n" );
document.write( "So the equation is this, using n for x:\r\n" );
document.write( "\r\n" );
document.write( "\"a%5Bn%5D=expr%28-1%2F3%29n%5E3%2B3n%5E2%2Bexpr%2816%2F3%29n%2B8\"\r\n" );
document.write( "\r\n" );
document.write( "Checking:\r\n" );
document.write( "\r\n" );
document.write( "for n=1\r\n" );
document.write( "\r\n" );
document.write( "\"a%5B1%5D=expr%28-1%2F3%29%281%29%5E3%2B3%281%29%5E2%2Bexpr%2816%2F3%29%281%29%2B8\"\r\n" );
document.write( "\"a%5B1%5D=expr%28-1%2F3%29%281%29%2B3%281%29%2Bexpr%2816%2F3%29%2B8\"\r\n" );
document.write( "\"a%5B1%5D=-1%2F3%2B3%2B16%2F3%2B8\"\r\n" );
document.write( "\"a%5B1%5D=-1%2F3%2B9%2F3%2B16%2F3%2B24%2F3\"\r\n" );
document.write( "\"a%5B1%5D=48%2F3\"\r\n" );
document.write( "\"a%5B1%5D=16\"\r\n" );
document.write( "\r\n" );
document.write( "for n=2\r\n" );
document.write( "\r\n" );
document.write( "\"a%5B2%5D=expr%28-1%2F3%29%282%29%5E3%2B3%282%29%5E2%2Bexpr%2816%2F3%29%282%29%2B8\"\r\n" );
document.write( "\"a%5B2%5D=expr%28-1%2F3%29%288%29%2B3%284%29%2Bexpr%2832%2F3%29%2B8\"\r\n" );
document.write( "\"a%5B2%5D=-8%2F3%2B12%2B32%2F3%2B8\"\r\n" );
document.write( "\"a%5B2%5D=-8%2F3%2B36%2F3%2B32%2F3%2B24%2F3\"\r\n" );
document.write( "\"a%5B2%5D=84%2F3\"\r\n" );
document.write( "\"a%5B2%5D=28\"\r\n" );
document.write( "\r\n" );
document.write( "for n=3\r\n" );
document.write( "\r\n" );
document.write( "\"a%5B3%5D=expr%28-1%2F3%29%283%29%5E3%2B3%283%29%5E2%2Bexpr%2816%2F3%29%283%29%2B8\"\r\n" );
document.write( "\"a%5B3%5D=expr%28-1%2F3%29%2827%29%2B3%289%29%2Bexpr%2848%2F3%29%2B8\"\r\n" );
document.write( "\"a%5B3%5D=-27%2F3%2B27%2B48%2F3%2B8\"\r\n" );
document.write( "\"a%5B3%5D=-27%2F3%2B81%2F3%2B48%2F3%2B24%2F3\"\r\n" );
document.write( "\"a%5B3%5D=126%2F3\"\r\n" );
document.write( "\"a%5B3%5D=42\"\r\n" );
document.write( "\r\n" );
document.write( "for n=4\r\n" );
document.write( "\r\n" );
document.write( "\"a%5B4%5D=expr%28-1%2F3%29%284%29%5E3%2B3%284%29%5E2%2Bexpr%2816%2F3%29%284%29%2B8\"\r\n" );
document.write( "\"a%5B4%5D=expr%28-1%2F3%29%2864%29%2B3%2816%29%2Bexpr%2864%2F3%29%2B8\"\r\n" );
document.write( "\"a%5B4%5D=-64%2F3%2B48%2B64%2F3%2B8\"\r\n" );
document.write( "\"a%5B4%5D=-64%2F3%2B144%2F3%2B64%2F3%2B24%2F3\"\r\n" );
document.write( "\"a%5B4%5D=168%2F3\"\r\n" );
document.write( "\"a%5B4%5D=56\"\r\n" );
document.write( "\r\n" );
document.write( "For more terms, calculate as above:\r\n" );
document.write( "\r\n" );
document.write( "16,28,42,56,68,76,78,72,56,28,-14,-72,-148,...\r\n" );
document.write( "\r\n" );
document.write( "Edwin

\n" ); document.write( " \n" ); document.write( "
\n" );