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If ∫(x+x2−1)2 dx=α⋅x+βx3+γ(x2−1)32+C\int (x + \sqrt{x^2 - 1})^2 \, dx = \alpha \cdot x + \beta x^3 + \gamma (x^2 - 1)^{\frac{3}{2}} + C, where CC is arbitrary constant, then the value of 3(α+β+γ)3(\alpha + \beta + \gamma) is

Solution

✅ Correct Option: 4

Expanding: (x+x2−1)2=x2+(x2−1)+2xx2−1=2x2−1+2xx2−1(x+\sqrt{x^2-1})^2 = x^2 + (x^2-1) + 2x\sqrt{x^2-1} = 2x^2 - 1 + 2x\sqrt{x^2-1}. Integrating term by term: ∫2x2dx=2x33\int 2x^2 dx = \frac{2x^3}{3}, ∫−1 dx=−x\int -1\, dx = -x, ∫2xx2−1dx=23(x2−1)3/2\int 2x\sqrt{x^2-1} dx = \frac{2}{3}(x^2-1)^{3/2}. So α=−1\alpha = -1, β=2/3\beta = 2/3, γ=2/3\gamma = 2/3. Then 3(α+β+γ)=3(−1+4/3)=13(\alpha+\beta+\gamma) = 3(-1 + 4/3) = 1.

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