Question

(1) If the roots of x2 + kr + 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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Answer 1

Answer:

(C) 0 or 4

Step-by-step explanation:

Given,

x² + Kx + k = 0

It is in the form,

ax² + bx + c = 0

Formula:

If the roots of the quadratic equation, ax² + bx + c = 0 are real and equal then b² - 4ac = 0.

Here a = 1, b = K, c = K

==> b² - 4ac = 0

==> K² - 4*1*K = 0

==> K² - 4K = 0

==> K(K - 4) = 0

==> K = 0 or K - 4 = 0

==> K = 0 or K = 4

So, Option (C) is the correct answer.

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