Question 469970: I have a student who is coming to me for tutoring for the Praxis I. Initially, I was supposed to be a writing tutor, but due to circumstances beyond my control, it has become necessary for me to tutor her in math as well. I am pretty decent with math, but there is one issue she is having that I can not, for the life of me, remember how to do. The question is this:
There is a picture of a graph that has a curve plotted on it.
The question asks, "Which of the following inequalities is represented by the graph above?"
I am given the following answer choices:
(Disclaimer - I do realize that these answer choices are equations, not inequalities, but I am merely quoting the study packet.)
A. y = x squared + 2
B. y = x squared - 2
C. y = x squared + 2x
D. y = x squared - 2x (correct, according to the answer key)
E. y = x squared + 2
While I realize that you do not have the graph to look at, could you please explain how to do these types of problems so that I can help my student? Thanks.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! y = x^2 is the following:
It touches the x-axis at (0,0)
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y = x^2+2 moves all the points up 2 ; crosses the y-axis at (0,2)
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y = x^2-2 moves all the points down 2 ; crosses the y-axis at (0,-2)
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y = x^2-2x = x(x-2) cuts the x-axis at x = 0 and x = 2
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y = x^2+2x = x(x+2) cuts the x-axis at x = 0 and x = -2.
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cheers,
Stan H
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