Question

Find the value/ s of k for which the quadratic equation 3x square+ kx +3 = 0 has real and equal roots

Answer 1

Answer:

k = 6 and k = -6

Step-by-step explanation:

The quadratic ax²+bx+c has equal roots only if the discriminant b²-4ac is zero.

So...

3x² + kx + 3 = 0  has equal real roots

=> k² - (4)(3)(3) = 0

=> k² = (4)(3)(3) = 36

=> k = ±6.

Answer 2

Answer:

Since the roots are real and equal, ∴ D = b

2 − 4ac = 0

⇒k

2 – 4×3×3 = 0 (∵ a = 3, b = k, c = 3)

⇒k

2 = 36

⇒k = 6 or −6