SOLUTION: what kind of roots does x^2+2x+8=0 have?

Click here to see ALL problems on Quadratic Equations

Question 244844: what kind of roots does x^2+2x+8=0 have?
Found 4 solutions by edjones, richwmiller, rapaljer, jsmallt9:
Answer by edjones(8007)   (Show Source):
You can put this solution on YOUR website!
x^2+2x+8=0
the determinant, b^2-4ac = 4-32 = -28
Because the determinant is negative the roots are imaginary.
.
Ed

Answer by richwmiller(17219)   (Show Source):
You can put this solution on YOUR website!
imaginary numbers

Answer by rapaljer(4671)   (Show Source):
You can put this solution on YOUR website!
x^2+2x+8=0

Calculate
b^2-4ac
2^2 -4*1*8
4-32 , which is a negative. Since this is negative, this means that you have complex roots.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida
Altamonte Springs Campus

Answer by jsmallt9(3758)   (Show Source):
You can put this solution on YOUR website!
I noticed that you have three solutions and two of them are slightly wrong. The correct answer is that the roots are complex.

Imaginary roots is not correct. Youcan find the roots using the quadratic formula:

From this formula we can see that:
The roots will have imaginary parts because, as the other solutions explain, is negative.
The roots will also have real parts because the "b" you have is not zero.

Roots that have both real and imaginary parts are complex roots (a + bi), not imaginary.