Question

If the roots of the quadratic equation px(x – 2) + 6 = 0 are equal, find the value of p.

Answer 1

It is given that the roots of the quadratic equation px² – 2px + 6 = 0 are equal. 

∴ D = 0 

⇒ (–2p)² – 4 × p × 6 = 0 

⇒ 4p² – 24p = 0 

⇒ 4p(p – 6) = 0 

⇒ p = 0 or p – 6 = 0 

⇒ p = 0 or p = 6 

For p = 0, we get 6 = 0, which is not true.  

∴ p ≠ 0 

Hence, the value of p is 6.