How do you write the vertex form equation of the parabola #y=x^2+2x-1#?
Send the constant(-1) to the left by doing,
Identify the coefficient of
In this case it's
Divide the cofficient by 2.
You get : 2/2 = color(red)1
We see that
And there you've got the vertex form of the equation of a parabola.
They call it vertex form simply because it gives us the cordinates of the vertex of the parabola that is being represented.
If we write it like this :
then the vertex can be read as