![Example 2 - Chapter 4 Class 11 Mathematical Induction - Part 2](https://d1avenlh0i1xmr.cloudfront.net/fd11c971-f522-4f95-856e-b3e9760c4d8f/slide2.jpg)
![Example 2 - Chapter 4 Class 11 Mathematical Induction - Part 3](https://d1avenlh0i1xmr.cloudfront.net/3e768932-faf8-4530-9317-faa362502cd2/slide3.jpg)
![Example 2 - Chapter 4 Class 11 Mathematical Induction - Part 4](https://d1avenlh0i1xmr.cloudfront.net/c5180bb6-26ed-4f65-baa6-3c42956e5a6b/slide4.jpg)
Examples
Last updated at April 16, 2024 by Teachoo
Example 2 Prove that 2𝑛>𝑛 for all positive integers n. Let P(n) : 2𝑛>𝑛 for all positive n For n = 1 L.H.S = 2𝑛 = 21 = 1 R.H.S = n = 1 Since 2 > 1 L.H.S > R.H.S ∴ P(n) is true for n = 1. Assume that P(k) is true for all positive integers k i.e. 2k> k We will prove that P(k + 1) is true. i.e 2𝑘 + 1> k + 1 From (1) 2k> k Multiplying by 2 on both sides. 2k × 2 > 2 × k 2.2k > 2 k 2k + 1 > k + k Now, k is positive We have proved P(1) is true So we have to prove for k > 1 k > 1 Adding k both sides k + k > k + 1 From (2) and (3) 2k + 1 > k + k and k + k > k + 1 Hence 2k + 1 > k + 1 ∴ L.H.S > R.H.S ∴ P (k + 1) is true whenever p(k) is true. ∴ By the principal of mathematical induction, P(n) is true for n, is a positive integer.