Added by Akpabio Udo on June 17, 2002 at 22:03:56:
Sum of sequence.
Sum of AP=n/2(2a+(n-1)d
Sum of GP=a(1-r^n)/1-r *When r is less than one.
a(1-r^n)/r-1 *when r is greater than 1.
Note that ^ means to the power of ..