posted by qwerty123 .
Can you explain why number 12 is D?
I don't know.
Here's a link to the site.
12. Suppose that a0 and a1 are real numbers, not both 0, and for n 2, an = jan1j an2. Then
the sequence an is always periodic with the same period. What is the least period?
A: 6 B: 7 C: 12 D: 9 E: none of the others