Mathematics I / Arithmetic and Geometric Sequences
Practice question · Multiple choice

An arithmetic sequence adds a fixed amount each step; a geometric one multiplies by a fixed factor. Why does that difference make geometric growth eventually overtake any arithmetic sequence, however large its common difference?

Hints
  1. Compare the SIZE OF THE STEP at term 10 and at term 1000 for each kind of sequence.
  2. Try 1000n against 2^n and find where the second overtakes.
Show the answer

A. Because a fixed step is eventually outpaced by one that keeps growing.

Why

The arithmetic sequence adds d at step 5 and at step 5000; the geometric one adds a proportion of its current value, so its increment grows exactly as fast as it does. Take 1000n against 2ⁿ: the arithmetic leads 10,000 to 1024 at n = 10 and trails 20,000 to a million at n = 20. Both are unbounded, the difference is the rate.

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