Question

Values of k for which the quadratic equation 2x - kx + k 0 has equal roots is
a)0only
b)4
c)8 only
d)0,8​

Answer 1

Answer:

The answer is D.

Step-by-step explanation:

We have to apply Discriminant Law. When a quadratic equation, ax² + bx + c = 0 has equal roots so the discriminant will be 0. Then, you have to substitute the values into the formula :

$D = {b}^{2} - 4ac$

$let \: D = 0 ,a = 2,b = k,c = k$

$0 = {k}^{2} - 4(2)(k)$

${k}^{2} - 8k = 0$

$k(k - 8) = 0$

$k = 0$

$k - 8 = 0$

$k = 8$