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Question
If the roots of x² + kx + k = 0 are real and equal, what is the value of k?
Options
0
4
0 or 4
2
Solution
0 or 4
X^2+kx+k has distinct real solution .
So, for distinct real solution
Use formula b^2 - 4ac>0
a = 1 , b= k , c = k
Put formula b^2– 4ac>0
K^2 - 4×1×k >0
K^2 - 4k>0
K(k-4)>0
K>0, k -4>0
K>0, k<4
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