Answer:
D) [tex]x^{2} + 2x + 3[/tex].
Step-by-step explanation:
All four polynomials are quadratic, meaning that the highest power of the unknown [tex]x[/tex] in the equation is two.
The sign of the quadratic discriminant, [tex]\Delta[/tex], is a way to tell if a quadratic polynomial comes with non-real solutions.
There are three cases:
How to find the quadratic discriminant?
If the equation is in this form:
[tex]a \; x^{2} + b\;x + c = 0[/tex],
where a, b, and c are real numbers (a.k.a. "constants.")
Quadratic discriminant:
[tex]\Delta = {b^{2} - 4\;a\cdot c}[/tex].
Polynomial in A:
[tex]x^{2} - 6x + 3 = 0[/tex].
[tex]\Delta = b^{2} - 4 \;a\cdot c = (-6)^{2} - 4\times 1\times 3 = 36 - 12 = 24[/tex].
[tex]\Delta > 0[/tex]. There will be no non-real solutions and two distinct real solutions.
Try the steps above for the polynomial in B, C, and D.