Question

7.
If one root of equation x2 - 3ax + f(a) = 0, is double of the other then f(x) is equal to :
(A)2x
(C) 2x2
(D) 3x2
(B) x2​

Answer 1

Answer:

C

Step-by-step explanation:

Let one root is alpha and acc. To qu. Second root is 2alpha then

Sum of roots =alpha+ 2 alpha

Product of roots = 2 alpha square

So, alpha +2 alpha =3a

3alpha=3a

Alpha=a ........ 1

Now 2alpha square =f(a)

2a2 =f(a),

2x2 =f(x)