Question

Find the value of k for the
equation 4xsquare + 4xk +
9=0 has equal roots.​

Answer 1

Answer:

Your answer is 12/3

Step-by-step explanation:

Given ,

4x^2+4xk+9=0

And given the roots of quadratic equation are equal.

So,

b^2-4ac=0

Where, a=4, b=4k, c=9

(4k) ^2-4(4) (9) =0

16k^2-144=0

16k^2=144

k^2=144/16

k=√144/16

K=12/4

Hope this is useful to you

Answer 2

Answer:

k= ±3

Step-by-step explanation:

α+β= -b/a   ---1

α*β= c/a    ---2

as, roots are equal α=β

from 1,

  2α= (-4k)/4

   α= -k/2

from 2,

  α²=9/4

squaring 1  we get α²= k²/4

comparing 1 and 2

(k²/4)=(9/4)

we get k=√9

      k=±3