y= -x to the second power minus 4x minus 1
I need to know if the parabola opens up or down and I need to know the vertex coordinates and the axis of symmetry of the function (8th grade math here)
I need to know if the parabola opens up or down and I need to know the vertex coordinates and the axis of symmetry of the function (8th grade math here)
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The parabola opens down because of the negative on the x. To find the vertex, you need to complete the square. It comes out to be y -3 = - ( x + 2 )^2. So the vertex is (-2,3). The axis of symmetry is x = -2.
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y = -x^2 - 4x - 1
We have to complete the square to find the vertex, so:
y = -(x^2 + 4x + 4 - 4) - 1
y = -(x + 2)^2 + 4 - 1
y = -(x + 2)^2 + 3
So the vertex is at (-2, 3), with the axis of symmetry being x = -2... It opens downward as the coefficient of x^2 (-1) is negative.
We have to complete the square to find the vertex, so:
y = -(x^2 + 4x + 4 - 4) - 1
y = -(x + 2)^2 + 4 - 1
y = -(x + 2)^2 + 3
So the vertex is at (-2, 3), with the axis of symmetry being x = -2... It opens downward as the coefficient of x^2 (-1) is negative.
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KAY SO -X 2 = X.
SO X - 4 - 1 = 3x
SO X - 4 - 1 = 3x