Question 194518: Name the vertex and axis of symmetry for each quadratic function. Tell wherther the parabola opens up, down, left, or right.
g(x)=-x^2-2x+8
Found 2 solutions by RAY100, stanbon:
Answer by RAY100(1637)   (Show Source):
You can put this solution on YOUR website! Let g(x) =y = x^2 -2x +8
,
positive leading coefficient means that it points up
,
x vertex is at x=-b/2a = -(-2)/2(1) =1
substitute in to get y,,,,y=1^2 -2*1 +8 = 7
Vertex is (1,7)
Axis of symmetry is x= 1
checking plot a few points,,,(1,7),,,(2,8),,,,(0,8),,,,,ok
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Name the vertex and axis of symmetry for each quadratic function. Tell wherther the parabola opens up, down, left, or right.
g(x)=-x^2-2x+8
-----------
When "x" gets very large, x^2 gets very, very large, but
negative x^2 getx very negative; so y gets very, very negative.
So the parabola opens downward.
------------------------------
Vertex, axis ??????
-x^2-2x + ? = y-8 + ?
-(x^2+2x+1) = y -8 -1
-(x+1)^2 = y-9
----
Vertex at (-1,9)
Axis of symmetry: x = -1
==============================
===============================
Cheers,
Stan H.
|
|
|
