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Match List-I with List-II

List-IList-II
(A) ∫01x21+x3dx\int_0^1 \frac{x^2}{1 + x^3} dx(I) 0
(B) ∫0π3sin⁡xdx\int_0^\pi 3\sin x dx(II) 2log⁡e(32)2\log_e\left(\frac{3}{2}\right)
(C) ∫−11sin⁡5xcos⁡6xdx\int_{-1}^1 \sin^5 x \cos^6 x dx(III) 6
(D) ∫234x2−1dx\int_2^3 \frac{4}{x^2 - 1} dx(IV) 13log⁡e2\frac{1}{3}\log_e 2

Choose the correct answer from the options given below:

Solution

✅ Correct Option: 3

(A) ∫01x21+x3dx\int_0^1 \frac{x^2}{1 + x^3} dx

Let u=1+x3u = 1 + x^3

du=3x2dxdu = 3x^2 dx

x2dx=13dux^2 dx = \frac{1}{3}du

When x=0x = 0: u=1+03=1u = 1 + 0^3 = 1

When x=1x = 1: u=1+13=2u = 1 + 1^3 = 2

∫1213udu\int_1^2 \frac{1}{3u} du

=13[ln⁡u]12= \frac{1}{3}[\ln u]_1^2

=13(ln⁡2−ln⁡1)= \frac{1}{3}(\ln 2 - \ln 1)

=13ln⁡2= \frac{1}{3}\ln 2

Therefore (A) → (IV)


(B) ∫0π3sin⁡xdx\int_0^\pi 3\sin x dx

∫0π3sin⁡xdx=3[−cos⁡x]0π\int_0^\pi 3\sin x dx = 3[-\cos x]_0^\pi

=3[(−cos⁡π)−(−cos⁡0)]= 3[(-\cos \pi) - (-\cos 0)]

=3[(−(−1))−(−1)]= 3[(-(-1)) - (-1)]

=3[1+1]= 3[1 + 1]

=6= 6

Therefore (B) → (III)


(C) ∫−11sin⁡5xcos⁡6xdx\int_{-1}^1 \sin^5 x \cos^6 x dx

Check if the function is odd by replacing xx with −x-x:

f(−x)=sin⁡5(−x)cos⁡6(−x)f(-x) = \sin^5(-x) \cos^6(-x)

=(−sin⁡x)5(cos⁡x)6= (-\sin x)^5 (\cos x)^6

=−sin⁡5xcos⁡6x= -\sin^5 x \cos^6 x

=−f(x)= -f(x)

Since the function is odd and the interval [−1,1][-1, 1] is symmetric, the integral equals 00.

Therefore (C) → (I)


(D) ∫234x2−1dx\int_2^3 \frac{4}{x^2 - 1} dx

4x2−1=4(x−1)(x+1)\frac{4}{x^2 - 1} = \frac{4}{(x-1)(x+1)}

Using partial fractions:

4(x−1)(x+1)=Ax−1+Bx+1\frac{4}{(x-1)(x+1)} = \frac{A}{x-1} + \frac{B}{x+1}

4=A(x+1)+B(x−1)4 = A(x+1) + B(x-1)

Put x=1x = 1: 4=2A4 = 2A so A=2A = 2

Put x=−1x = -1: 4=−2B4 = -2B so B=−2B = -2

∫23(2x−1−2x+1)dx\int_2^3 \left(\frac{2}{x-1} - \frac{2}{x+1}\right) dx

=2[ln⁡∣x−1∣−ln⁡∣x+1∣]23= 2[\ln|x-1| - \ln|x+1|]_2^3

=2[ln⁡∣x−1x+1∣]23= 2\left[\ln\left|\frac{x-1}{x+1}\right|\right]_2^3

=2[ln⁡24−ln⁡13]= 2\left[\ln\frac{2}{4} - \ln\frac{1}{3}\right]

=2[ln⁡12−ln⁡13]= 2\left[\ln\frac{1}{2} - \ln\frac{1}{3}\right]

=2ln⁡32= 2\ln\frac{3}{2}

=2log⁡e32= 2\log_e\frac{3}{2}

Therefore (D) → (II)


The correct matching is:

(A) → (IV)

(B) → (III)

(C) → (I)

(D) → (II)

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