SOLUTION: Would someone be able to help me through a couple of these so I can get a better grip on how to do them? Determine the number of solutions to the quadratic equation using the di

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Would someone be able to help me through a couple of these so I can get a better grip on how to do them? Determine the number of solutions to the quadratic equation using the di      Log On


   

Question 59260: Would someone be able to help me through a couple of these so I can get a better grip on how to do them?
Determine the number of solutions to the quadratic equation using the discriminant to determine if the answers are real or complex. (no need to find the roots, just the numer & solution type)
i. 2x^2+5x+5=0
ii. 3z^2+z-1=0
Many thanks!
Answer by funmath(2933) About Me  (Show Source):
You can put this solution on YOUR website!

Determine the number of solutions to the quadratic equation using the discriminant to determine if the answers are real or complex. (no need to find the roots, just the numer & solution type)
:
The discriminant of a quadratic equation written in standard formax%5E2%2Bbx%2Bc is highlight%28b%5E2-4ac%29 Notice that this is just the inside of the square root in the quadratic equation.
If the discriminant is positive there are 2 real solutions.
If the discriminant is 0 there is one real solution.
If the discriminant is negative there are 2 complex solutions.
:
i. 2x^2+5x+5=0
a=2, b=5,c=5 The discriminant is
%285%29%5E2-4%282%29%285%29
25-40
-15 negative. There are 2 complex solutions.
:
ii. 3z^2+z-1=0
a=3, b=1,c=-1 The discriminant is
%281%29%5E2-4%283%29%28-1%29
1%2B12
13 positive. There are two real solutions.
Happy Calculating!!!