Question

the value of k for which equation 9 x 2 + 8 x k + 8 equal to zero has equal roots is option A only 3 option B minus 3 option C plus minus 3 option d 9​

Answer 1

Answer: k = ± 3/√2

Either question is different or option should be different.

Step-by-step explanation:

For quadratic equation,

9x^2+8xk+8=0, we have

a= 9, b= 8k , c =8

For equal roots, D= 0

D=b^2-4ac

So,

b^2-4ac=0

Putting values of mya, b, c, we get

(8k)^2-4×9×8=0

64k^2-32×9=0

32( 2k^2-9) =0

So, 2k^2-9=0

2k^2 =9

k^2 =9/2

k= ± √(9/2)

k = ± 3/√2