find k,if has real nd equal roots x^2+k(2x+k-1)+2=0
Answers
Question :-
Find value of k if it has real and equal roots ,
•x² +k(2x + k - 1) + 2 = 0
Answer :-
→ k = 2
To find :-
→ Value of k
Formula used :-
Discriminant = (b² - 4ac)
Explanation :-
If given any Quadratic p(x) = ax²+ b x +x
c= 0 ,has equal and real roots then it's discriminant (D) is equal to zero(0) .
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Given equation is ,
→x² + k(2x + k -1) +2 = 0
→ x² +2kx +( k² - k +2) = 0
Comparing this equation with given p(x)
we get,
→ a = 1 , b = 2k and c = k² - k +2
Now ,apply the given formula for discriminant ,
→ D = 0
→ b² - 4ac = 0
→(2k)² -4 ×1(k² - k +2 ) = 0
→ 4k² - 4k² + 4k - 4×2 = 0
→ 4k - 8 = 0
→ 4k = 8
divided by 4 on both sides ,
→ k = 2
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Some similar questions for practice :-
Q.1 If "a" and "b" are the roots of the equation x² + 4x -12 = 0 then find -
→ Sum of roots
→Product of roots
→Discriminant
→Nature of roots .
Q.2 If roots of the polynomial 2x² + 2a+2a(x + 2) + 4 = 0 are real and equal then find value of "a" .
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