Question

If the equation x² + 4x + k = 0 has real and distinct roots, then

Options

• k < 4

• k > 4

• k ≥ 4

• k ≤ 4

Answer 1

The given quadric equation is x² + 4x + k = 0, and roots are real and distinct.

Then find the value of k.

Here, a = 1, b = 4 and , c = k

As we know that `D = b^2 - 4ac`

Putting the value of  a = 1, b = 4 and , c = k

` (4)^2 - 4 xx 1 xx k `

= 16 - 4k

The given equation will have real and distinct roots, if D > 0

 16 - 4k > 0

        4k < 16

        ` k< 16/4`

             < 4

Therefore, the value of  k < 4 .