Given the geometric sequence where a1 = 3 and the common ratio is −1, what is the domain for n

Answer 1

Mark is right, of course, but I'll just add that this question looks like it's designed to mislead you. The domain of a sequence is ALWAYS n is an element of positive integers +Z, or in other words, 1, 2, 3, 4, ..., etc. UNLESS STATED OTHERWISE.

Remember, domain is input, and sequences are almost always functions of 1, 2, 3, etc. Put in 1 to get the first term; put in 2 to get the second term, and so on.

It's easy to look at this one and start figuring out the actual terms of the sequence, but if it asks for domain, it's almost always "positive integers."

Answer 2

n is a element of the positive integers, ⁺Z.