Question

Find the values of k for which the roots are real and equal in each of the following equation:

kx² + 4x + 1 = 0

Answer 1

The given quadric equation is kx² + 4x + 1 = 0, and roots are real and equal

Then find the value of k.

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

As we know that D = b² - 4ac

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

D = (4)² - 4(k)(1)

= 16 - 4k

The given equation will have real and equal roots, if D = 0

Thus,

16 - 4k = 0

4k = 16

k = 16/4

k = 4

Therefore, the value of k = 4.