If the roots of x² + kx + k = 0 are real and equal, what is the value of k?
(A) 0 (B) 4 (C) 0 or 4 (D) 2
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Answered by
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For the equation to have real and equal roots D should be equal to 0..
D=b²+4ac
In the equation x²+kx+k
a=1
b=k
c=k
D=k²-4k
D=0
k²-4k=0
k(k-4)=0
k=0. or k=4
Answer is (C)
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Answered by
3
(C) 0 or 4
If the roots are real and equal, so the polynomial is a perfect square.
Here, the coefficient of x^2 is 1.
So the coefficient of x^0, i.e., k, is the square of half of coefficient of x, i.e., k.
Which means the following:
_________________________________________
If is a perfect square,
then,
_________________________________________
Okay.
In
So the answer is either 0 or 4.
Let's check.
If k = 0,
If k = 4,
Hope this helps you.
Plz mark it as the brainliest.
Plz ask me if you've any doubts.
Thank you. :-))
If the roots are real and equal, so the polynomial is a perfect square.
Here, the coefficient of x^2 is 1.
So the coefficient of x^0, i.e., k, is the square of half of coefficient of x, i.e., k.
Which means the following:
_________________________________________
If is a perfect square,
then,
_________________________________________
Okay.
In
So the answer is either 0 or 4.
Let's check.
If k = 0,
If k = 4,
Hope this helps you.
Plz mark it as the brainliest.
Plz ask me if you've any doubts.
Thank you. :-))
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