Match List-I with List-II
|
List-I |
List-II |
|
(A) $\int\limits_0^1\frac{x^2}{1 + x^3} dx$ |
(I) 0 |
|
B) $\int\limits_0^{\pi}3\sin x\, dx$ |
(II) $2\log_e(\frac{3}{2})$ |
|
(C) $\int\limits_{-1}^1\sin^5x \cos^6 x\, dx$ |
(III) 6 |
|
(D) $\int\limits_2^3\frac{4}{x^2-1}dx$ |
(IV) $\frac{1}{3}\log_e 2$ |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A)-(IV), (B)-(III), (C)-(I), (D)-(II)
|
List-I |
List-II |
|
(A) $\int\limits_0^1\frac{x^2}{1 + x^3} dx$ |
(IV) $\frac{1}{3}\log_e 2$ |
|
B) $\int\limits_0^{\pi}3\sin x\, dx$ |
(III) 6 |
|
(C) $\int\limits_{-1}^1\sin^5x \cos^6 x\, dx$ |
(I) 0 |
|
(D) $\int\limits_2^3\frac{4}{x^2-1}dx$ |
(II) $2\log_e(\frac{3}{2})$ |
Evaluate each integral:
(A) $\int_0^1 \frac{x^2}{1 + x^3} \, dx$
Let $x^3 = t$ ⟹ $3x^2 dx = dt$ ⟹ $\frac{1}{3} \int \frac{dt}{1 + t} = \frac{1}{3} \ln(1 + x^3)$
So, value = $\frac{1}{3} \ln(2)$⟹ matches (IV)
(B) $\int_0^\pi 3 \sin x \, dx = 3[-\cos x]_0^\pi = 3[-(-1) - (-1)] = 6$ ⟹ matches (III)
(C) $\int_{-1}^1 \sin^5 x \cos^6 x \, dx$ is an odd function (since $\sin^5 x$ is odd and $\cos^6 x$ is even). Hence integral over symmetric interval is 0 ⟹ matches (I)
(D)
Now integrate: \[ \int_{2}^{3} \left( \frac{2}{x - 1} - \frac{2}{x + 1} \right) dx = 2 \int_{2}^{3} \left( \frac{1}{x - 1} - \frac{1}{x + 1} \right) dx \]
Now integrate: $2 \int_{2}^3 \left( \frac{1}{x - 1} - \frac{1}{x + 1} \right) dx = 2[\ln|x - 1| - \ln|x + 1|]_{2}^3$
$= 2 \left( \ln\left(\frac{1}{2}\right) - \ln\left(\frac{1}{3}\right) \right) = 2 \ln\left(\frac{3}{2}\right)$⟹ matches (II)