How can you tell when a quadratic equation has two identical, rational solutions?
When the radicand is negative
When b in the quadratic formula is greater than the radicand
When the radicand equals zero
When the radicand is not a perfect square

Question

How can you tell when a quadratic equation has two identical, rational solutions?
When the radicand is negative
	When b in the quadratic formula is greater than the radicand
	When the radicand equals zero
	When the radicand is not a perfect square

anonymous · Answer

The discriminant of the equation will be zero.

anonymous · Answer

Which I suppose in your question is called the radicand.

anonymous · Answer

You can see this from the quadratic equation.  Assuming, of course, that the equation has rational coefficients...

anonymous · Answer

In ax^2+bx+c=0 
when b^2-4ac=0 
c is correct

directrix · Answer

@becca9898 

Discriminant Study Chart Attached.