Question 363 of 455MediumMCQ
If both roots of x2−2kx+k2+k−5=0 are less than 5, then k lies in the interval Solutions · 1
Official solution
(i) D≥0⟹k≤5; (ii) f(5)>0⟹(k−5)(k−4)>0; (iii) vertex <5⟹k<5.
Combining these gives k∈(−∞,4). Answer the question to unlock