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Statement-1: For every natural number n ...

Statement-1: For every natural number `n ge 2, (1)/(sqrt1)+(1)/(sqrt2)+…..(1)/(sqrtn) gt sqrtn`
Statement-2: For every natural number `n ge 2, sqrt(n(n+1) lt n+1`

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To solve the given problem, we need to analyze both statements and prove their validity step by step. ### Step 1: Analyze Statement 1 **Statement 1:** For every natural number \( n \geq 2 \), \[ \frac{1}{\sqrt{1}} + \frac{1}{\sqrt{2}} + \ldots + \frac{1}{\sqrt{n}} > \sqrt{n} \] **Proof:** 1. **Base Case:** Let's check for \( n = 2 \): \[ \frac{1}{\sqrt{1}} + \frac{1}{\sqrt{2}} = 1 + \frac{1}{\sqrt{2}} > \sqrt{2} \] Since \( 1 + \frac{1}{\sqrt{2}} \approx 1.707 > 1.414 \), the base case holds. 2. **Inductive Step:** Assume the statement is true for \( n = k \): \[ \frac{1}{\sqrt{1}} + \frac{1}{\sqrt{2}} + \ldots + \frac{1}{\sqrt{k}} > \sqrt{k} \] We need to prove it for \( n = k + 1 \): \[ \frac{1}{\sqrt{1}} + \frac{1}{\sqrt{2}} + \ldots + \frac{1}{\sqrt{k}} + \frac{1}{\sqrt{k+1}} > \sqrt{k + 1} \] By the inductive hypothesis: \[ > \sqrt{k} + \frac{1}{\sqrt{k+1}} \] We need to show: \[ \sqrt{k} + \frac{1}{\sqrt{k+1}} > \sqrt{k + 1} \] Squaring both sides: \[ k + 2\frac{\sqrt{k}}{\sqrt{k+1}} + \frac{1}{k+1} > k + 1 \] Simplifying gives: \[ 2\frac{\sqrt{k}}{\sqrt{k+1}} + \frac{1}{k+1} > 1 \] This inequality holds true for \( k \geq 2 \). Thus, by induction, Statement 1 is true for all \( n \geq 2 \). ### Step 2: Analyze Statement 2 **Statement 2:** For every natural number \( n \geq 2 \), \[ \sqrt{n(n+1)} < n + 1 \] **Proof:** 1. **Base Case:** Check for \( n = 2 \): \[ \sqrt{2 \cdot 3} = \sqrt{6} < 3 \] This is true since \( \sqrt{6} \approx 2.45 < 3 \). 2. **Inductive Step:** Assume it holds for \( n = k \): \[ \sqrt{k(k+1)} < k + 1 \] We need to prove it for \( n = k + 1 \): \[ \sqrt{(k + 1)(k + 2)} < k + 2 \] Squaring both sides: \[ (k + 1)(k + 2) < (k + 2)^2 \] Expanding both sides: \[ k^2 + 3k + 2 < k^2 + 4k + 4 \] Simplifying gives: \[ 2 < k + 2 \] This is true for \( k \geq 2 \). Thus, by induction, Statement 2 is true for all \( n \geq 2 \). ### Conclusion Both statements are true for every natural number \( n \geq 2 \). ---
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