Question

How do I solve this if the axis of symmetry is a fraction? ( Unit 8: Quadratic Equations, Homework 2: Graphing Quadratic Equations )

Answer 1

Remember that the axis of symmetry is found with

`x=(-b)/(2a)`

In the equation
`y=3x^2-5`, there's a missing middle term:

`y=3x^2{\boldsymbol{{}+0x}}-5`

Your b-value in this situation is 0, so your formula is

`x=(-(0))/(2(3))=(0)/(6) =0`

So the axis of symmetry is the y-axis.

Now with that, you can also find the vertex by substituting in 0 for x:

y = 3(0)^2 - 5 = 0 - 5 = -5

The vertex is (0,-5).