How do you graph the parabola #y=x^2 - 4x +7# using vertex, intercepts and additional points?

1 Answer
Nov 7, 2016

The vertex is #(2,3)#
The y intercept is #(0,7)#

Explanation:

let's rewrite the equation in the vertex form
#y=x^2-4x+4+7-4=(x-2)^2+3#
#(x-2)^2=y-3#
The equation of a parabola is #(x-a)^2=2p(y-b)#
Here #2p=1##=>##p=1/2#
So the vertex is #(2,3)#
The focus is #(2,7/2)#
And the directrix is #y=5/2#
The y intercept is when #x=0##=>#y=7#
graph{x^2 -4x+7 [-9.62, 12.88, -0.31, 10.95]}