Question

What is the condition for common root in quadratic equation

Answer 1

What are the 2 roots of a quadratic equation ?

Answer 2

No in general i am talking

Answer 3

Actually, my query was a more general one :|
So, what are the 2 roots of a quadratic equation ?

Answer 4

Let one root be alpha the other beta

Answer 5

In the quadratic equation ax^2 + bx + c =0, what are the values of alpha and beta ? In terms of a,b,and c

Answer 6

I want the general form i heard there is one
There are no specific values of alpha and beta

Answer 7

Can you please re-phrase your question ? Do you mean you are given 2 quad. eqns and there is a common root ?
Or you have a quadratic eqn and both roots are equal ?

And also, alpha = (-b + sqrt(b^2- 4ac))/2a , beat = (-b - sqrt(b^2- 4ac))/2a

Answer 8

2 quad. eqns and there is a common root

Answer 9

I see. Well you can always derive that
Let the 2 eqns be ax^2 + bx + c =0 and px^2 + qx + r =0
let the common root be t.
Then,
at^2 + bt + c =0 and pt^2 + qt + r =0
You have to eliminate t from the 2 eqns to derive a resourceful condition

Answer 10

i see thanks !

Answer 11

glad to help ^^