Answer:
D
Step-by-step explanation:
Quadratic has a general form of:
[tex]ax^2 + bx + c = 0[/tex]
The quadratic given here is:
[tex]y = x^2 + 3x + 1[/tex]
Matching it with the general form, we can see that:
a = 1 [coefficient of x^2]
b = 3
c = 1
Now, if we look at the formula for axis of symmetry, we can easily solve this out. The axis of symmetry is given by:
Axis of Symmetry is [tex]x=-\frac{b}{2a}[/tex]
We know a = 1 and b = 3, so we have:
[tex]x=-\frac{b}{2a}\\x=-\frac{3}{2(1)}\\x=-\frac{3}{2}[/tex]
Hence,
D is the correct answer.
