x^ +k (2x + k-1) + 2 = 0 find value of k for which quadratic equation
Answers
But as far as I know the question is this....
See the attachment....
This might be the solution
Question:
Find the value of k for which the quadratic equation x² + k(2x + k - 1) + 2 = 0 has equal roots.
Answer:
k = 2
Note:
• An equation of degree 2 is know as quadratic equation .
• Roots of an equation is defined as the possible values of the unknown (variable) for which the equation is satisfied.
• The maximum number of roots of an equation will be equal to its degree.
• A quadratic equation has atmost two roots.
• The general form of a quadratic equation is given as , ax² + bx + c = 0 .
• A quadratic equation has atmost two roots .
• The discriminant of the quadratic equation is given as , D = b² - 4ac .
• If D = 0 , then the quadratic equation would have real and equal roots .
• If D > 0 , then the quadratic equation would have real and distinct roots .
• If D < 0 , then the quadratic equation would have imaginary roots .
Solution:
The given quadratic equation is ;
x² + k(2x + k - 1) + 2 = 0 .
=> x² + 2kx + k² - k + 2 = 0
Clearly , we have ;
a = 1
b = 2k
c = k² - k + 2
We know that ,
The quadratic equation will have real and equal roots if its discriminant is zero .
=> D = 0
=> (2k)² - 4•1•(k²-k+2) = 0
=> 4k² - 4•(k²-k+2) = 0
=> 4•[k² - (k²-k+2)] = 0
=> k² - k² + k - 2 = 0
=> k - 2 = 0
=> k = 2
Hence,
The required values of k is 2 .