document.write( "Question 159183: My math teacher has asked me to find the n^th term for the fourth diagonal in Pascal's Triangle. Basicly, he has asked me to find a formula that will find the next number for the fourth diagonal. I've tried all sorts of charts to derieve a formula but none have yeilded any. \n" ); document.write( "
Algebra.Com's Answer #117306 by gonzo(654)![]() ![]() ![]() You can put this solution on YOUR website! the equation for the 3d diagonal is given as: \n" ); document.write( " \n" ); document.write( "the equation for the 4th diagonal is given as: \n" ); document.write( " \n" ); document.write( "----------------------------------------- \n" ); document.write( "try these websites. \n" ); document.write( "the first one describes pascal's triangle. \n" ); document.write( "the second one actually give you equations to calculat the nth term. \n" ); document.write( "------------------------------------------- \n" ); document.write( "the first website is: http://www.mathsisfun.com/tetrahedral-number.html \n" ); document.write( "the second website is: http://noticingnumbers.net/220PASCALStriangle.htm \n" ); document.write( "----------------------------------------- \n" ); document.write( "the formulas i provided you are taken from the second website and manipulated so the manual calculations are easier. \n" ); document.write( "------------------------------------------- \n" ); document.write( "a test of the formulas for the 9th term is constructed below. \n" ); document.write( "the answer should be 45 for the 3d diagonal and 165 for the 4th diagonal. \n" ); document.write( "-------------------------------------------- \n" ); document.write( "for the 3d diagonal, the formula for the 9th term (n = 9) yields \n" ); document.write( "(10*9)/2 which equals 90/2 which equals 45 which is correct. \n" ); document.write( "--------------------------------------------- \n" ); document.write( "for the 4th diagonal, the formula for the 9th term (n = 9) yields \n" ); document.write( "(11*10*9)/6 = 990/6 = 165. \n" ); document.write( "---------------------------------------------- \n" ); document.write( "these formulas actually work !!!!! \n" ); document.write( "hopefully this is what you were looking for.\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |