Expert: Sherman D. - 2/2/2006

Question
1.Which term is the linear termin the equation y=2x^2-3x+5 ?
2.Identify the vertex of the parabola defined by y=2x^2+8x+9 ?
3. Identify the line of symmetry of the parabola defined by y=-2(x+4)^2+6
4. Identify the direction of the opening of the parabola defined by y=2x-8-x^2
Identify the y-intercept for the equation defined by y=(x-1)^2+2
5. When solving a quadratic equation by graphing , we find the roots using which of the following ?
A)vertex
B)x-intercept
C)y-intercept
D)none of the above

Answer
1.)
I'm not certain what you mean by linear term, since i can't ever remember having to know what it is.
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2.)
y = 2x^2 + 8x + 9

x = -b/(2a)
x = (-8)/(2(2))
x = -8/4
x = -2

y = 2(-2)^2 + 8(-2) + 9
y = 2(4) - 16 + 9
y = 8 - 16 + 9
y = -8 + 9
y = 1

Vertex is (-2,1)

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3.)
y = -2(x + 4)^2 + 6
y = -2(x + 4)(x + 4) + 6
y = -2(x^2 + 8x + 16) + 6
y = -2x^2 - 16x - 32 + 6
y = -2x^2 - 16x - 26
y = -2(x^2 + 8x + 13)

x = (-b)/(2a)
x = (-(8))/(2(1))
x = -8/2
x = -4

Line of Symmetry is x = -4

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5.)
The roots are found by finding the x-intercepts

To graph it, you will need both the x-intercepts and vertex, so my answer will probably by B.) x-intercept