If -2 is the root of the quadratic equation x2-px-2=0 and the quadratic equation x2+px+2λ=0 has equal roots,then value of 8λ is given by 

please answer fast i have exam on day after tommorow and please explain complete soultion

 

 

Hi Prakhar!
Here is the answer to your query.
 
It is given that –2 is a root of the quadratic equation x2px –2 = 0
 ∴  (–2)2p (–2) –2 = 0
⇒ 4 + 2p – 2 = 0
⇒ 2p + 2 =0
⇒ 2p = –2
p = –1
 
It is given that quadratic equation x2 + px + 2l = 0 has equal roots
D = 0
p2 – 4 × 1 × 2l = 0
⇒ (–1)2 – 8l = 0
⇒ 1 – 8l = 0
⇒8l = 1
 
Thus, the value of 8l is 1
 
Hope! This will help you.
Cheers!!!

  • -1

Putting the value inplace of x.

(-2)2 -p x -2 = 0

4 + 2p = 0

p = -2

now in the 2nd equ.

x2 -2x +2λ = 0

D = 0

(-2)2 - 4 x 1 x 2λ = 0

λ = 1/2 ......Hope this help u!!!!

  • 1

your answer is wrong the answer is 1 

  • 2

Hey sorry.Actually putting 2 in 1st step Value of p is -1...& the othr u cn fnd it out acc. to the steps...

  • -2
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