Q48 / 90 · KVPY 2017 (19 Nov SB/SX) · Mathematics
Define a function $f(x)=\frac{16 x^{2}-96 x+153}{x-3}$ for all real $x \neq 3$. The least positive value of $f(x)$ is
- A16
- B18
- C22
- Correct answerD24
Solution
$y=\frac{16 x^{2}-96 x+153}{x-3}$
make it quadratic in $\mathrm{x}$
$\begin{array}{l}
16 x^{2}-x(96+y)+(153+3 y)=0 \\
D \geq 0
\end{array}$
Solve $y^{2}-576 \geq 0$
$\mathrm{y} \in(-\infty,-24] \cup[24, \infty)$
So, least positive is 24
Hence, the correct answer is option: 'D'.