The axis of symmetry is the line that divides the parabola into two congruent sides.
Given the quadratic equation: y=ax² + bx + c.
If b = 0, then the equation is: y=ax² + c.
The axis of symmetry can be found using the equation:
[tex]x=-\frac{b}{2a}[/tex]Since b = 0:
[tex]x=-\frac{0}{2a}=0[/tex]So, the axis of symmetry is x = 0.
Answer: x = 0.