find a formula for the general term (n) of these sequences. show all your calculations/workings.
a) -10; -8; -5; -1; ........
The common differnces are: +2, +3, +4, or
a2 = a1 + 2
a3 = a2 + 3
a4 = a3 + 4
from which it can be seen that the general term is,
a_(n+1) = a_n + (n+1)
b) -10; -8; -4; 2; ..........
The common differences are: +2, + 4, + 6, or
a2 = a1 + 2
a3 = a2 + 4
a4 = a3 + 6
from which it can be seen that the general term is,
a_(n+1) = a_n + 2n