Q255 / 270 · NDA 2020 · Mathematics
What is the value of $k$ such that integration of $\frac{3 x^2+8-4 k}{x}$ with respect to $x$, may be a rational function?
- A0
- B1
- Correct answerC2
- D-2
Solution
$I=\int\left(\frac{3 x^2+8-4 k}{x}\right) \cdot d x$
$\begin{aligned}
& =\int 3 x d x+\int \frac{8-4 k}{x} \cdot d x \\
& =\frac{3}{2} x^2+(8-4 k) \cdot \ln (x)+C
\end{aligned}$
where $C=$ constant
To get integration as rational function,
$(8-4 k) \cdot \ln (x)=0 \Rightarrow 8-4 k=0 \Rightarrow k=\frac{8}{4}=2$
Hence, the correct answer is option: 'C'.