Question

Find the value of ‘k’ for which the following quadratic equation has real roots:

x² + kx + 4 = 0

Answer 1

Given:

x² + kx + 4 = 0

a = 1

b = k

c = 4

The discriminant `D = b^2 − 4ac = k^2 − 16`

 For real roots, we need D ≥ 0, so

`k^2 − 16 ≥ 0`

`⇒ k^2 ≥ 16 `

`⇒ k ≤ −4 or k ≥ 4`