Question

Choose the correct answer from the given four options :

The value(s) of k for which the quadratic equation 2x² – kx + k = 0 has equal roots is (are)

पर्याय

• 0 only

• 4

• 8

•  0, 8

Answer 1

2x² – kx + k = 0
a = 2, b = -k, c = k
∴ b² - 4ac
= (-k)² - 4 x 2 x 4
= k² - 8k
∴ Roots are equal.
∴ b² - 4ac = 0
k² - 8k = 0
⇒ k(k - 8) = 0
Either k = 0
or
k - 8 = 0,
then k = 8
k = 0, 8.