Which sequence could be partially defined by the recursive formula f (n + 1) = f(n) + 2.5 for n ≥ 1?

2.5, 6.25, 15.625, 39.0625, …
2.5, 5, 10, 20
–10, –7.5, –5, –2.5, …
–10, –25, 62.5, 156.25

Option C: –10, –7.5, –5, –2.5, … is the sequence that could be partially defined by the recursive formula

Explanation:

The given recursive formula is for and

We need to determine the sequence.

The sequence can be determined by substituting n = 1, 2, 3, 4,....

2nd term of the sequence:

Substituting n = 1 in the formula , we get,

Simplifying, we have,

Thus, the 2nd term of the sequence is -7.5

3rd term of the sequence:

Substituting n = 2 in the formula , we get,

Simplifying, we have,

Thus, the 3rd term of the sequence is -5

4th term of the sequence:

Substituting n = 3 in the formula , we get,

Simplifying, we have,

Thus, the 4th term of the sequence is -2.5

Therefore, the sequence is –10, –7.5, –5, –2.5, …

Hence, Option C is the correct answer.

you didn't post any answer choices, so its not 100% clear what your teacher is looking for

however, log(15/7) is equivalent to log(15) - log(7)

i'm using the rule log(x/y) = log(x) - log(y)