What is the axis of symmetry and vertex for the graph y=x28x+3?

1 Answer
Apr 20, 2016

Vertex(x,y)(4,13)
Axis of symmetryx=4

Explanation:

Standard form: y=ax2+bx+c

Write as: y=a(x2+bax)+c

With a quadratic, the axis of symmetry passes through xvertex

In the case of this question a=1

xvertex=(12)×ba (12)×(8)=+4
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By substitution:

yvertex=(4)28(4)+3=13
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Vertex(x,y)(4,13)
Axis of symmetryx=4

Tony B