If 2 is a root of the equation x^2+bx+12=0 and the equation has equal roots , find the value of b .
( P.S for each of the hints that i use i get a different value of b that to extremely different)
Thank you

Hi Ayesha,

Kindly find the answer to your query:

If 2 is a root of equation x² + bx + 12 = 0 then the value x = 2 must satisfy the equation.

Now, putting x = 2

(2)² + (b)(2) + 12 = 0

$\Rightarrow$ 4 + 2b + 12 = 0
$\Rightarrow$ 2b = - 16
$\Rightarrow$ b = - 8 ..... (i)

Also in the given question, the quadratic equation has equal roots. In this case,

$\Rightarrow$b² - 4ac = 0
$\Rightarrow$b² = 4ac

Here, b= co-efficient of x
a = coefficient of x²
c = constant

Therefore, (b)² = 4$\times$1$\times$12
$\Rightarrow$(b)² = 48

$\Rightarrow$b =  4$\sqrt{3}$ ..... (ii)

From equation (i) and (ii), we are getting different values of 'b'. Thus, there seems some error in the posted query.

Kindly re-check and post your query again so that we can assist you with the proper solution.

Also, follow the link given below since it is a similar query answered by our experts and it might help you to frame you query in proper format:

https://www.meritnation.com/ask-answer/question/if-2-is-a-root-of-the-quadratic-equation-x2-px-5-0-and-t/surface-areas-and-volumes/3840526

Hope it will help you clear your doubts and do get back to us after re-framing your query.

Regards