Question

What is true about the solutions of a quadratic equation when the radicand of the quadratic formula is zero?

Answer 1

Two identical rational solutions ^

Answer 2

The quadratic formula is $\frac{-b +/- \sqrt{b^2 - 4ac} }{2a}$

If the square root in the numerator is equal to 0, we are left with $\frac{-b +/- 0}{2a}$

when you do the plus or  minus, the answers will be the same since you are adding and subtracting 0. Therefore there will be two identical rational solutions.