## anonymous one year ago Calculate the discriminant to determine the number of real roots. y = x2 + 3x + 9 How many real roots does the equation have? A. two real roots B. no real roots C. one real root D. no solution to the equation

1. anonymous

@LynFran

2. amoodarya

$\sqrt{b^2-4ac}=\sqrt{3^2-4*9*1}$

3. anonymous

so A there are two real roots?

4. SolomonZelman

Ok, I will tell you this. The discriminant for any quadratic in a form of: $$\color{black}{ \displaystyle y=a{\rm x}^2+b{\rm x}+c }$$ is: $$\large\color{black}{ \displaystyle {\rm D}=\sqrt{b^2-4ac} }$$

5. SolomonZelman

So, if the discriminant is: an integer - then you can factor the quadratic a real number (not 0, and not integer) - then you just have 2 real roots. an imaginary number (that results from a negative in a square root) - then no real roots, rather, only 2 imaginary roots.

6. anonymous

for people that see this in the future its B