Working With A Graph

Discussion in 'Other Pre-University Math' started by nycmathguy, Jul 6, 2021.

  1. nycmathguy

    nycmathguy

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    See attachment.

    Part (a)

    Domain = All real numbers

    Range = All real numbers

    Part (b)

    Zero of f at the point (3, 0). Thus, x = 0 is the only zero of the function.

    Part (c)

    Increasing: (-4, 1) to (0, 9)

    Decreasing: (0, 9) to (3, 0)

    Increasing: (3, infinity)

    How do we use the graph to do parts (c) and (d)?

    20210706_031127.jpg
     
    nycmathguy, Jul 6, 2021
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  2. nycmathguy

    MathLover1

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    Part (a)

    Domain => take a look on x-axis an you see that the courve starts at x=-4 and goes very close to x=5 (there you see a hole)

    so, domain is [-4,5)

    Range => [0,9]

    Part (b)
    correction:
    Zero of f at the point (3, 0).=>correct

    Thus, x = 0 is the only zero of the function.=>incorrect,
    the point (3, 0) tells you that x=3 and y=0

    recall definition of zero: the value of x for what y=0 (or f(x)=0)


    Part (c)

    Increasing: (-4, 1) to (0, 9)
    correction: no need to name points, all you need is say that increasing [-4,0]

    Decreasing: (0, 9) to (3, 0)
    all you need is say that increasing [0,3]

    Increasing: (3, infinity)=>incorrect
    Increasing: [3, 5)

    (d)

    minimum is at point (3,0)
    maximum is at point (0,9)

    (e)
    The graph of an even function is symmetric about the y- axis.
    The graph of an odd function is symmetric about the origin.

    in your case the graph is not symmetric about the y- axis nor is symmetric about the x- axis

    so, f is neither
     
    MathLover1, Jul 6, 2021
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  3. nycmathguy

    nycmathguy

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    Wonderful, detailed reply.
    This is precisely what I am seeking.

    1. Is my effort incorrect?

    2. If incorrect, why?

    3. I will not post daily questions. I often forget that you have a life outside of mathematics.

    4. I will post less questions but would like to see a more detailed reply to each thread.
     
    nycmathguy, Jul 7, 2021
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  4. nycmathguy

    MathLover1

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    your solution and my corrections:
    Part (a)

    Domain = All real numbers=> incorrect

    Range = All real numbers=> incorrect


    Part (b)

    Zero of f at the point (3, 0). => correct
    Thus, x = 0 is the only zero of the function.=> incorrect


    Part (c)

    Increasing: (-4, 1) to (0, 9)=>correction: no need to name points, all you need is say that increasing [-4,0]

    Decreasing: (0, 9) to (3, 0)=>correction: all you need is say that increasing [0,3] (we are lookine for x values)

    Increasing: (3, infinity)=>incorrect
    correction:Increasing: [3, 5)
     
    MathLover1, Jul 7, 2021
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  5. nycmathguy

    nycmathguy

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    Ok.
     
    nycmathguy, Jul 7, 2021
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