Ummmmmmmmmmmmm
Mm A is correct I think. The question was unclear but A is the only correct function
B and C are absurd; if a series converges, it must have a sum, but if a series diverges, it cannot have a sum.
Now, notice that
That is, we can write the sum more compactly as
The series is geometric with common ratio
, so the series converges (and thereby has a sum), so the answer is D.
Coefficient of 14x is 14
Coefficientis the number in front of the letter. For example, coeffient of 2b is 2. When there is no number in front of the letter the coefficient is 1.