6th q
Hi!
Here is the answer to your question.
The given quadratic equation is
(x – a) (x – b) + (x – b) (x – c) + (x – a) (x – c) = 0
⇒ x2 – ax – bx + ab + x2 – bx – cx + bc + x2 – cx – ax + ca = 0
⇒ 3x2 – 2(a + b + c) x + (ab + bc + ca) = 0
Discriminant, D = [–2 (a + b + c)]2 – 4 × 3 × (ab + bc + ca)
= 4 (a+ b + c)2 – 12 (ab + bc + ca)
= 4 (a2+ b2 + c2 + 2ab + 2bc + 2ca – 3ab – 3bc – 3ca)
∴ D > 0. So, the roots the given quadratic equation are real.
When a = b = c, D = 2 × 0 = 0.
Thus, the roots of the given quadratic equation are equal.
Cheers!