What is the sixth term in the following arithmetic sequence 13 2 -9 -20?
Any number you like.If you fit a linear equation, Un = 24 - 11n then the 6th term is 42.However,Vn = (-29x4 + 290x3 - 1015x2 + 790x + 744)/60 gives the sequence 13, 2, -9, -20, -42.6, and -100Wn = (7x4 - 70x3 + 245x2 - 570x + 648)/20 gives the sequence 13, 2, -9, -20, -22.6, and 0whileXn = (71x4 - 710x3 + 2485x2 - 4210x + 3144)/60 gives the sequence 13, 2, -9, -20, -2.6, and 100By suitable choice of polynomial, any number at all can be in sixth place.