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Use mathematical induction to prove n< 2^n

User Eddyuk
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To prove the statement using mathematical induction:

**Base Case:**

When n=1, the statement becomes 1 < 2^1, which is true.

**Inductive Hypothesis:**

Assume that for some integer k, k < 2^k.

**Inductive Step:**

We need to show that k+1 < 2^(k+1).

We know that k < 2^k by our inductive hypothesis. Also, we know that 2^k < 2^k+1 because multiplying a number by 2 is equivalent to shifting its binary representation to the left by one position.

Therefore,

k < 2^k < 2^k+1

Adding 1 to both sides of the inequality chain, we get:

k+1 < 2^k+1

Multiplying both sides by 2, we get:

2(k+1) < 2^(k+1)

Since 2^(k+1) = 2*2^k, we get:

2(k+1) < 2*2^k

k+1 < 2^k

This completes the inductive step.

Therefore, by mathematical induction, the statement n < 2^n is true for all positive integers n.
User Kritzefitz
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