Answer: 4.
- A 4
- B 1
- C 2
- D 10
Correct answer: A. 4
Explanation: At n = 4, 24 > 16; for n = 3, 6 < 8, so the result holds from n = 4 onward.
Mathematical induction works like a row of dominoes: proving the base case P(1) tips the first domino, and proving the inductive step (P(k) ⟹ P(k+1)) guarantees each domino knocks over the next - together these two facts guarantee ALL dominoes fall, without checking each one individually.
Concept context
A proof technique used to establish that a statement is true for every natural number, using a base case and an inductive step.