Consider the equation x^2+8x+-4=0.
Without solving the quadratic explain how you know if the equation has real or imaginary solutions.
\(\text{For a quadratic equation }a x^2 + b x + c = 0 \\ \\ \text{a non-negative discriminant, i.e. }\\ D=b^2 - 4 a c \\ \text{indicates real roots}\)
\(\text{the discriminant in this case is } \\ D=64+16 = 80 > 0 \\ \text{and thus we have real roots}\)
