The final result is 3 x 81 243. A n a 1 n 1d. Since we get the next term by adding the common difference the value of a2 is just.
We can think of an arithmetic sequence as a function on the domain of the natural numbers.
The idea is to try to reduce to geometric sequences. It is a linear function because it has a constant rate of change. Our mission is to provide a free world-class education to anyone anywhere. We want to find a such that the sequence u n a n is geometric of parameter a it is the most natural choice because if b 0 we already are in this case.