Question

If 2 is a root of the equation x² + ax + 12 = 0 and the quadratic equation x² + ax + q = 0 has equal roots, then q =

(a) 12
(b) 8
(c) 20
(d) 16

Answer 1

is the common roots given quadric equation are , and

Then find the value of q.

Here, ….. (1)

….. (2)

Putting the value of in equation (1) we get

Now, putting the value of in equation (2) we get

Then,

As we know that

Putting the value of

The given equation will have equal roots, if

Thus, the correct answer is