document.write( "Question 868395: For the sequence 2, 9, 28, 65,... How do I find the next term and the rule for the nth term \n" ); document.write( "
Algebra.Com's Answer #523515 by jim_thompson5910(35256)![]() ![]() ![]() You can put this solution on YOUR website! Subtract 1 from each term to get \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "2-1 = 1 \n" ); document.write( "9-1 = 8 \n" ); document.write( "28-1 = 27 \n" ); document.write( "65-1 = 64\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Each number on the right hand side (RHS) is a perfect cube\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1 = 1^3 \n" ); document.write( "8 = 2^3 \n" ); document.write( "27 = 3^3 \n" ); document.write( "64 = 4^3\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the rule is \"cube the number, then add 1\". We add 1 to undo the subtraction of 1 we did in the first part (see above)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the rule is \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Once you get the general rule or formula, it's always a good idea to test it with the given sequence you already have. For instance, the third term is given to be 28. So if we did things right, then plugging n = 3 into the formula should give 28. Since \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The next term would be when \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Note: you can do each part in any order, but I find it easier to find the general rule/formula first. \n" ); document.write( " |