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Let f(x)=∫3x−2(x+1)2(x+3)dx=αlog⁡∣x+1x+3∣+β(1x+1)+γf(x)=\int \frac{3x-2}{(x+1)^2(x+3)}dx = \alpha\log\left|\frac{x+1}{x+3}\right|+\beta\left(\frac{1}{x+1}\right)+\gamma, where γ\gamma is the constant of integration. If f(0)=114log⁡(13)+4f(0)=\frac{11}{4}\log\left(\frac{1}{3}\right)+4, then which of the following are correct?

(A) 4α+2β+6γ=224\alpha+2\beta+6\gamma=22

(B) f(1)=α[1−log⁡2]f(1)=\alpha[1-\log 2]

(C) α+β+γ=274\alpha+\beta+\gamma=\frac{27}{4}

(D) γ=−52\gamma=-\frac{5}{2}

Choose the correct answer from the options given below:

Solution

✅ Correct Option: 4

Partial fractions give 11/4x+1−5/2(x+1)2−11/4x+3\frac{11/4}{x+1}-\frac{5/2}{(x+1)^2}-\frac{11/4}{x+3}.

Integrating, α=114\alpha=\frac{11}{4} and β=52\beta=\frac52. Using f(0)f(0): 114log⁡13+52+γ=114log⁡13+4\frac{11}{4}\log\frac13+\frac52+\gamma=\frac{11}{4}\log\frac13+4, so γ=32\gamma=\frac32.

Then (A) gives 25≠2225\ne22 and (D) fails, while f(1)=114(1−log⁡2)f(1)=\frac{11}{4}(1-\log2) and α+β+γ=274\alpha+\beta+\gamma=\frac{27}{4} hold.

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