Solve: $\int \frac{6x}{x^2 + 2} dx + \int \frac{4}{x(x^2 + 2)} dx$ |
$3 \ln (x^2 + 2) + 2 \ln |x| + C$ $\ln |x^2 + 2| + 2 \ln |x| + C$ $2 \ln |x| - 2 \ln (x^2 + 2) + C$ $2 \ln |x(x^2 + 2)| + C$ |
$2 \ln |x(x^2 + 2)| + C$ |
The correct answer is Option (4) → $2 \ln |x(x^2 + 2)| + C$ $I = \int \frac{6x}{x^2 + 2} dx + \int \frac{4}{x(x^2 + 2)} dx$ First integral: $\int \frac{6x}{x^2 + 2} dx$ Using substitution $u = x^2 + 2, du = 2x dx$, the integral simplifies to: $3 \ln |x^2 + 2| + C_1$ Second integral: Decompose $\frac{4}{x(x^2 + 2)}$ using partial fractions: $\frac{4}{x(x^2 + 2)} = \frac{2}{x} - \frac{2x}{x^2 + 2}$ Integrate both parts: $\int \frac{2}{x} dx = 2 \ln |x|$ $\int \frac{2x}{x^2 + 2} dx = \ln |x^2 + 2|$ Second integral becomes: $2 \ln |x| - \ln |x^2 + 2| + C_2$ Combine the two integrals: $3 \ln |x^2 + 2| + (2 \ln |x| - \ln |x^2 + 2|)$ $= 2 \ln |x^2 + 2| + 2 \ln |x|$ $= 2 \ln (|x(x^2 + 2)|) + C$ |