Question

Find the equation for the axis of symmetry for f(x)=2x^2 + 3x + 9

x = -4

x = 4/3

x = −3/4

x = 3

Answer 1

x = -3/4

Explanation:

The quadratic function:

`f(x)=ax^2+bx+c`

The equation of an axis of symmetry:

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

We have:

`f(x)=2x^2+3x+9\\\\a=2,\ b=3,\ c=9`

Substitute:

`x=(-3)/(2(2))=-(3)/(4)`

Answer 2

Explanation:

So the equation used to find the axis of symmetry in a quadratic function is

x = -b / 2a

So our b term is = 3

and our a term is = 2

So:

-3 / 2(2)

or

x = -3 / 4