Multiple choice

If discriminant of a quadratic equation is $D=0,$ then ___________is not possible for its roots $\alpha$ and $\beta$.

  1. $\alpha =\beta$
  2. $\alpha-\beta=0$
  3. $\alpha+\beta=2\alpha$
  4. $\alpha+\beta=0$
Reveal answer Fill a bubble to check yourself
D Correct answer
AI explanation

When the discriminant D = 0, the roots of the quadratic equation are real and equal, meaning alpha = beta. This makes alpha - beta = 0 and alpha + beta = 2alpha logically true. However, alpha + beta = 0 would imply the sum of two identical non-zero numbers is zero, which is a contradiction, making it impossible.