
William W. answered 02/12/19
Math and science made easy - learn from a retired engineer
For the quadratic equation given by:
ax^2 + bx + c = 0
the answer (x) is given by:
The discriminant is given by the portion under the radical:
b^2 - 4ac
This discriminant tells us about the nature of the roots (values of x). If it is negative then you will be taking the square root of a negative number which is not a real number, In that case, the roots are imaginary (and there are 2 of them).
If the discriminant is equal to zero, since the square root of zero is zero, there will be just 1 answer, x = -b/(2a).
If the discriminant is a positive number, there will be two real root answers.
In this case the discriminant is:
[ (-8)^2 -4(2)(1)] = 64 - 8 = 56
so there are two real root solutions.