Question

The axis of symmetry for a function in the form `f(x) = x^2 + 4x − 5` is `x = −2`. What are the coordinates of the vertex of the graph?

Answer 1

Vetex `->(x,y)=(-2,-9)`

Explanation:

Given that `x_("vertex")=-2`

Set `y=f(x)=x^2+4x-5`

Substitute (-2) wherever you see an `x`

`color(green)( y= color(red)(x)^2+4color(red)(x)-5color(white)("dddd")->color(white)("dddd") y= color(red)((-2))^2+4color(red)((-2))-5`

`color(green)(color(white)("ddddddddddddddddd")->color(white)("dddd") y=+4color(white)("dddd")-8color(white)("d.d")-5`

`y_("vertex")=-9`

Vetex `->(x,y)=(-2,-9)`