Q144 / 225 · JEE Main 2005 · Mathematics
If both the roots of the quadratic equation $x^2-2 k x+k^2+k-5=0$ are less than 5 , then $\mathrm{k}$ lies in the interval
- A$(5,6]$
- B$(6, \infty)$
- Correct answerC$(-\infty, 4)$
- D$[4,5]$
Solution
$$
\begin{aligned}
& \frac{-b}{2 a} < 5 \\
& f(5)>0 \\
& \Rightarrow k \in(-\infty, 4) .
\end{aligned}
$$
Hence, the correct answer is option: 'C'.