[JEE Main 2005] if both roots of x 2 2kx k 2 k 5 0 are less
If both roots of $x^2-2kx+k^2+k-5=0$ are less than $5$, then $k$ lies in
(a) $(5,6]$
(b) $(6,\infty)$
(c) $(-\infty,4)$
(d) $[4,5]$
1 Answer
VAVidaara Admin
✓ Vidaara Team
✓ Accepted
· 2d ago
▲ 0
Correct answer: (c) $(-\infty,4)$
Need $D\ge0$ ($k\le5$), vertex $k<5$, and $f(5)=k^2-9k+20=(k-4)(k-5)>0$ ($k<4$). Together $k<4$.
JEE Main 2005 · Quadratic Equations and Inequations — verified solution by the Vidaara Team.
Log in to post your own answer or join the discussion.
No comments yet — start the discussion.