54916912
An antiderivative of a rational function is
\(F(x)=3\ln|x-2|-2\ln|x+1|\).
Find \(F'(x)\) as one rational expression. Then state the corresponding indefinite integral.
Hints
- Differentiate each logarithmic term separately.
- Combine the resulting simple fractions using one common denominator.
- Check the numerator after distributing both coefficients.
Solution
1. Differentiate the logarithms: \(F'(x)=\frac{3}{x-2}-\frac{2}{x+1}\).
2. Use the common denominator \((x-2)(x+1)\).
3. The numerator is \(3(x+1)-2(x-2)=x+7\).
4. Therefore \(F'(x)=\frac{x+7}{(x-2)(x+1)}\), and its indefinite integral is \(3\ln|x-2|-2\ln|x+1|+C\).
Answer
\(F'(x)=\frac{x+7}{(x-2)(x+1)}\)
\(\int\frac{x+7}{(x-2)(x+1)}\,\text{d}x=3\ln|x-2|-2\ln|x+1|+C\)
