Question

For what value of k the roots of the following equation are equal
x² + kx +9=0​

Answer 1

Answer:

The given quadratic equation is x

2

−kx+9=0, comparing it with ax

2

+bx+c=0

∴ We get, a=1b=−k,c=9

⇒ It is given that roots are real and distinct.

∴ b

2

−4ac≥0

⇒ (−k)

2

−4(1)(9)≥0

⇒ k

2

−36≥0

⇒ k

2

≥36

⇒ k≥6 or k≤−6

Answer 2

Answer:

k = -6

Step-by-step explanation:

Let roots of the eqn be a & a

considering roots to be equal

a + a = 2a = -k .......(1) sum of roots

a(a) = 9 .........(2) product of roots

a^2 = 9

a =3

put a=3 in eqn (1)

2(3) = - k

k = -6

Mark it branliest if you understand