Question

for what values of k the roots of the equation x^2+4x+k=0 are real(cbse2019)​

Answer 1

Answer:

• Given equation. = x²+4x+k=0

So to find the value of k also there is a condition given the roots are real ..So for this the descriminent of the equation may be greater then zero or equal to zero.

•°• D ≥ 0

b²-4ac ≥ 0

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

so b²-4ac= 16-4k

so , 16-4k ≥ 0

=> -4k ≤ -16

=> 4k ≤ 16

=> k ≤ 4

• The value if k may be equal to 4 or less then 4