\(\int\displaystyle\frac{3x+2}{(x+1)(x+2)}\,dx\) is equal to
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → \(-\log|x+1|+4\log|x+2|+C\)
By partial fractions, let
\( \displaystyle \frac{3x+2}{(x+1)(x+2)} = \frac{A}{x+1}+\frac{B}{x+2} \)
\( 3x+2 = A(x+2)+B(x+1) \)
Putting x = −1:
\( -1 = A \)
Putting x = −2:
\( -4 = -B \), so \( B = 4 \)
So
\( \displaystyle \int\frac{3x+2}{(x+1)(x+2)}\,dx = \int\left(\frac{-1}{x+1}+\frac{4}{x+2}\right)dx \)
\( = -\log|x+1|+4\log|x+2|+C \)