Find the values of k for each of the following quadratic equations, so that they have two equal roots. (i) 2×2 + kx + 3 = 0 (ii) kx (x – 2) + 6 = 0

Solutions:

Comparing the given equation with  , we get,

As we know, Discriminant

For equal roots, we know,

Discriminant = 0

 

Comparing the given equation with  , we get

We know, Discriminant

For equal roots, we know,

However, if k = 0, then the equation will not have the terms ‘x²‘ and ‘x‘.

Therefore, if this equation has two equal roots, k should be 6 only