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
Manish Khanna Grade: 10
        

21_30198_1.JPG

6 years ago

Answers : (3)

vikas askiitian expert
510 Points
										

sol-1


    here we have to use  three conditions,


  1)   f(k) > 0                      (K=3 in this question)


 2)   D > = 0


 


from 1 , f(3) > 0


         a2 - 5a + 6 > 0


       (a-3)(a-2) > 0


from this we can say , value of a should be


        a > 3  , a < 2


 


 from 2 , D> = 0


      4a2 > = 4(a2+a-3)


       a-3 < = 0


       a < =  3                  ..................2


 


these all conditions are satisfied if a < 2


so option  a is correct

6 years ago
vikas askiitian expert
510 Points
										

ax2 + bx +c = 0


in this quadratic expression


 sum of roots = -b/a


        product = c/a


we have eq , 2x2 - 3x - 6 = 0


 let x,y are the roots of this eq then


 x+y = -b/a = 3/2


 xy = c/a = -3


 


x2+y2 = (x+y)2 - 2xy


x2+y2 = (3/2)2 - 2(-3) = 9/4+6 = 33/4          ........................1


 


now , eq whose roots are (x2+2 , y2+2) will be


 [X - (x2+2)][X-(y2+2)] = 0


 X2 - X(x2+y2+4) + x2y2 + 2(x2+y2) + 4 = 0


x2+y2 = 33/4 & xy = -3  so 


X2 - X(49/4) + 59/2 = 0


4X2 - 49X + 59 = 0


this is the required quadratic equation ...


 


approve if u like my ans


 


 

6 years ago
Pramod J AskiitiansExpert-IIT-B
36 Points
										

Dear student,


for real roots b^2 - 4ac > 0


=> 4a^2 - 4a^2 - 4a + 12 > 0


=> a<3


for a = 3 roots of equation are 3,3


so option a is correct.

6 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies
  • Complete JEE Main/Advanced Course and Test Series
  • OFFERED PRICE: Rs. 15,900
  • View Details
Get extra Rs. 3,180 off
USE CODE: CART20
Get extra Rs. 466 off
USE CODE: CART20

Ask Experts

Have any Question? Ask Experts

Post Question

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