Aditya Gupta
Last Activity: 5 Years ago
note that the graph of y= f(x)= x^2 + (1 - 2k)x + (k^2 - k - 2) would be an upward parabola. so, a necessary and sufficient condition for 3 to lie in between roots is f(3) should be less than 0. this is in effect the same as applying intermediate value theorem as f is continuous.
here, f(3)= 9 + 3(1 – 2k) + k^2 - k - 2 must be less than 0.
or k^2 – 7k + 10 must be less than 0.
or (k – 2)(k – 5) must be less than 0.
so that Ans: k should lie in (2, 5).
your option A and C are wrongly typed so idk what they are.
but D is definitely wrong and B is partially correct.
anways, the ques has been answered.
kindly approve :)