00:01
Okay, so now let's look at this problem number 16.
00:03
Okay, i will have this fn equals to 3 to the 2 is.
00:07
I want to prove that this sequence is a geometric sequence.
00:13
Okay, so what i do is first i want to write down f1.
00:20
So f1 equals to e to 2 times 1 equals to e to the 2s or e squared.
00:27
Okay, so the next step is i want to write down.
00:31
F n and f n minus 1 okay f n equals to 3 to the 2 n's f of n minus 1 equals to 3 to the 2 times m minus 1 okay or you can write as 3 to the 2 n minus 2 so now i want to find the ratio between fn and f n minus 1 okay so i have f n over f n minus 1 equals to 3 to the 2 ns over 3 to the 2 n's minus 2.
01:07
Okay, which equals to 3 squared, it is 9, right? so we know that 9 is not 0.
01:19
Okay, so we see that the ratio of successive terms is now 0 and it's constant equals to 9.
01:31
Okay, so we see that the sequence, fn, is geometric and the common ratio is 9...