00:01
Here we're given an infinite series and we want to use the ratio test to see if it converges or diverges.
00:04
So we have the sum of 2 to the k times x minus 3 to the k over k.
00:11
Sorry, we're looking for the interval of convergence.
00:13
Doesn't really change anything though.
00:14
So let's go ahead and take the a sub k plus 1.
00:17
That's 2 to the k times 2.
00:19
That's 2 to the k plus 1.
00:20
And then we have x minus 3 to the k plus 1.
00:22
That's to the k and then times itself again.
00:25
And then we'll divide by k plus 1.
00:27
That's a sub k plus 1.
00:29
Then i want to divide by a sub k, which is really the same as multiplying by the reciprocal.
00:33
So k over 2 to the k times x minus 3 to the k...