Question

The value of discriminant of a quadratic equation is 0. Then the roots of such an equation are

• A. real
• B. imaginary
• C. equal
• D. unequal

Answer 1

Answer: (A), (C)

The correct options are
A real
C equal

For equation $a{x}^2+bx+c=0$, expression $b^2-4ac$ is called discriminant and is denoted by D.
If D>0, then the equation has real and unequal roots.
If D=0, then the equation has real and equal roots.
If D<0, then the equation has imaginary and unequal roots.

Since it is given that D = 0, the roots must be real and equal.