I am assuming that you actually mean "axis of symmetry"

Note. For a quadratic function in the Vertex Form: f(x) = a(x - h)^2 + k

The equation for the axis of symmetry is x = h

The quadratic function f(x) = (x + 2)^2 - 4 is in vertex form. Meaning we can compare with f(x) = a(x - h)^2 + k to get our value of 'h'. Then we can use this value to obtain your equation for the function's axis of symmetry.

f(x) = (x + 2)^2 - 4 <Given quadratic function. It is in vertex form>

f(x) = a(x - h)^2 + k <Compare give quadratic function with the vertex form>

x + 2 = x - h <We would compare the expressions in parenthesis>

x + 2 - x = x - h - x <Subtract both sides by x>

2 = -h

-2 = h <Negate both sides>

h = -2

Now that we have our value of h, we can obtain our equation for the axis of symmetry

x = h <Equation for the axis of symmetry>

x = -2 <Substitute the value of h>

SOLUTION: Equation for the axis of symmetry is x = -2

Nov 11th, 2014

Did you know? You can earn $20 for every friend you invite to Studypool!