00:01
We have the sum of a sequence in which the nth term of the sequence is written as 4 times 3 to the n minus 1.
00:08
All right, so with this in mind, let's determine what this sum is.
00:11
Well, we actually have a formula given in the book.
00:14
It states that this sum is going to be the first term multiplied by 1 minus the common ratio to the n power, divided by 1 minus the common ratio.
00:25
So what are the common ratio and the first term? well, according to the book as well, we have that any sequence can be written in a form remarkably similar to what we see in this sum, where the first term, the four is our initial term, a1, and then whatever term is raised to a power, in this case the three is our common ratio.
00:47
So with this in mind, we can determine the sum...