Question

What is the axis of symmetry of the graph of y=x^2-3x+9?

Answer 1

`x=3/2`

the axis of symmetry of a parabola `y=ax^2+bx+c` is given by `x=-b/2a` (it's a vertical line), because `-b/2a` is the `x` of vertex of the parabola, and you know the axis is vertical and passes through the vertex, so you're done: `x=-(-3/2) => x=3/2`