SOLUTION: I need help with a graphing question: I can't paste the graph, but the x intercepts are approximately -1 and 3. The Y intercept is -2. I'm asked to find the equation that rep

Algebra ->  Graphs -> SOLUTION: I need help with a graphing question: I can't paste the graph, but the x intercepts are approximately -1 and 3. The Y intercept is -2. I'm asked to find the equation that rep      Log On


   

Question 1038933: I need help with a graphing question:
I can't paste the graph, but the x intercepts are approximately -1 and 3. The Y intercept is -2.
I'm asked to find the equation that represents the graph and I'm given the following equations:
A. y = x^2 – 2x – 2
B. y = –x^2 + 2x – 2
C. y = 2x^2 – 3x – 2
D. y = –2x^2 + x – 2
I'm also asked to state the range, the vertex and state the interval on which the function is decreasing.
I really appreciate any help you can offer, thank you!
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


Each of the 4 given functions has a -intercept of . You can tell this by the fact that the constant term is -2. The graph of any quadratic of the form has a -intercept of .

The two functions with negative lead coefficients, namely answers B and D, both open downward and have vertices below the -axis. Therefore, neither one has any -intercepts.

As for the other two answers, it depends on what you mean by 'approximately' when you describe the -intercepts. Answer A has intercepts of and . Answer C has intercepts of and . From what you posted, I can't tell which is the correct answer. Perhaps you can get it from the figure below.



John

My calculator said it, I believe it, that settles it