Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • School
  • If -5 is a root of the quadratic equation  and the quadratic equation <img alt="p ( x^2 + x )+ k = 0" src="https:

If -5 is a root of the quadratic equation 2x^2 + px -15 = 0 and the quadratic equation p ( x^2 + x )+ k = 0  has equal roots, find the value of k. 

 

 

 

 
 
 
 
 

Answers (1)

(-5) is root of 2x^2 + px -15 = 0 \\\\ 

-5 will satisfy the equation   2x^2 + px -15 = 0 \\\\

2 ( -5) ^ 2 + P \times ( -5) -15 = 0 \\\\ 2 \times 25 -5 p -15 = 0 \\\\ 50 - 5p - 15 = 0 \\\\ 5 p = 35 \\\\ p = 7

Also  

p (x ^2 + x ) + k = 0  has equal roots 

7 ( x^2 + x ) + k = 0 \\\\ 7x^2 + 7 x + k = 0 \\\\

for equal roots 

b^2 = 4ac \\\\ 7^2 = 4 \times 7 \times k \\\\ k = 7/4

 

Posted by

Ravindra Pindel

View full answer

Similar Questions

Trending Articles/News

anam-khan

CBSE Result 2025: DigiLocker access code out; schools to download for Class 10, 12 students
anam-khan

CBSE Class 10, 12 result process revised; answer book photocopy now comes before re-evaluation
anam-khan

CBSE Class 10 result 2025 not expected this week, 'confirms' Board amid ruckus over result date

Latest Question