Question

How can you tell when a quadratic equation has two identical, rational solutions?

Answer 1

For solutions to be rational, discriminant must be zero, or a perfect square. For solutions to be rational AND identical, discriminant must be zero.

Answer 2

so the answer is when the radicand equals zero

Answer 3

?

Answer 4

yes

Answer 5

okay thanks

Answer 6

if the radicand (aka discriminant ) \(b^2-4ac=0\) then the quadratic formula tells you the zeros are \(-\frac{b}{2a}\) aka the vertex. it also means you have a perfect square, like say \((x-4)^2=0\)