A discriminant of -17 indicates what type of roots?

A. Two Irrational
B. Two Complex
C. Two Rational
D. One Rational Double

Question

A discriminant of -17 indicates what type of roots?

A. Two Irrational	
	 B. Two Complex	
	 C. Two Rational	
	 D. One Rational Double

muzzack · Answer

One real root.

If the coefficients of the quadratic are rational then it will be a rational root

anonymous · Answer

How did you get that answer? and the answer wasn't one of the choices?

anonymous · Answer

@iambatman @Muzzack @ParthKohli @amistre64

muzzack · Answer

no im not giving the anser out im just giving you a hint

amistre64 · Answer

do you recall the 'formula' for the discriminant?

anonymous · Answer

Okay but I don't understand the hint so can you walk me through it?

parthkohli · Answer

The discriminant is known to be quite an essential term appearing in the quadratic formula.$$x=\dfrac{-b \pm \sqrt{\color{#C00}{b^2 - 4ac}}}{2a}$$One thing which we can clearly, very clearly observe is that this term is enclosed within a square root.  What does that mean to you?  What will happen if the discriminant becomes $-17$?

anonymous · Answer

Here is the table that the lesson came with

amistre64 · Answer

so they give you a table which tells us the answer ....

hartnn · Answer

so you have a negative discriminant
search for the row in your table that has a negative discriminant
look for 'type and Number of roots' in that row.