MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Grade: 11
        
The value of k for which the number 3 lies between the roots of equation x^2 + (1 - 2k)x + (k^2 - k - 2) = 0 is given by
A) 2
B) k > 2
C) 2
D) k > 5
[Full Explaination needed]
one month ago

Answers : (3)

Aditya Gupta
1670 Points
							
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 :)
one month ago
Shadow The Hedgehog
23 Points
							
Sir, I think there was a problem in placing the options
The Updated Options are
A) 2<k<5
B) k > 2
C) 2<k<3
D) k > 5
one month ago
Aditya Gupta
1670 Points
							
yeah so obviously option A is correct as it is the same as (2, 5).
if any other doubt, feel free to ask.
 kindly approve :)
one month ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies


Course Features

  • 731 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution


Course Features

  • 54 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions


Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details