SOLUTION: 2. Calculate the discriminant to determine the number of real roots. y = x^2 + 3x + 9 How many real roots does the equation have? (Points : 5) A. One real root B. Two real

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: 2. Calculate the discriminant to determine the number of real roots. y = x^2 + 3x + 9 How many real roots does the equation have? (Points : 5) A. One real root B. Two real       Log On


   

Question 941422: 2. Calculate the discriminant to determine the number of real roots.
y = x^2 + 3x + 9
How many real roots does the equation have? (Points : 5)
A. One real root
B. Two real roots
C. No real roots
D. No solution to the equation
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

y+=+x%5E2+%2B+3x+%2B+9 =>In this case a=1,b=3,c=9
The discriminant is b%5E2-4ac+=3%5E2-4%2A3%2A9=9-108=-99:
If the value is b%5E2-4ac+%3E0 and a Perfect Square there are Two Real Rational Solutions
If the value is b%5E2-4ac+%3E0 and is not a Perfect Square there are Two Real Irrational Solutions
If the value is b%5E2-4ac=0 there is One Real Solution
If the value is b%5E2-4ac%3C0 there are No Real Solutions, there are Two Imaginary Solutions
in your case b%5E2-4ac=-99 which is < then 0;
so, answer is C. No real roots