Translations of graphs need help

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  1. iceman95's Avatar
    • Respected Member
    • Posts: 150
    Translations of graphs need help
    Can someone reflect these in the y-axis please?

    y=2x^3+x^2-5x+1

    y=3sin(x)

    And can someone stretch these parallel to the x axis please

    y=x^2 by scale factor 3 parallel to the x-axis

    y=x^2-4x+1 by scale factor 0.5 parallel to the x axis

    y=3sin(x) by scale factor 1/5 parallel to the x-axis

    45 minutes ago
    - 4 days left to answer.
  2. Hopple's Avatar
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    • Location: London
    Re: Translations of graphs need help
    A reflection in the y axis is to swap around the positive and negative sides of the x axis.

    To stretch f(x) by a factor of a along the x axis, you need f(x) to come at a*x, hence you get the stretch being f(x/a). The division by a means x has to be a times as large to get the same value of f.
  3. rommy123's Avatar
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    • Posts: 230
    Re: Translations of graphs need help
    agree to that ^^^^^
  4. ztibor's Avatar
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    Re: Translations of graphs need help
    (Original post by iceman95)
    Can someone reflect these in the y-axis please?

    y=2x^3+x^2-5x+1

    y=3sin(x)

    And can someone stretch these parallel to the x axis please

    y=x^2 by scale factor 3 parallel to the x-axis

    y=x^2-4x+1 by scale factor 0.5 parallel to the x axis

    y=3sin(x) by scale factor 1/5 parallel to the x-axis

    45 minutes ago
    - 4 days left to answer.
    Generally:
    let y=f(x)
    THen
    Reflection in the y-axis: y=f(-x)
    Reflection in the x-axis:y=-f(x)
    Translating by 'a' parallel to the x: y=f(x-a)
    Translating by 'a' parallel to the y: y=f(x)+a
    Streching by scale factor 'a' parallel to x: y=f(\frac{1}{a}x)
    Streching by scale factor 'a' parallel to y: y=a\cdot f(x)

    F.e for 2nd
    y=sin3x \rightarrow y=sin(-3x)=-sin3x
    for 4th
    y=x^2-4x+1 \rightarrow y=\left (2x)^2-4(2x)+1=4x^2-8x+1
  5. iceman95's Avatar
    • Respected Member
    • Posts: 150
    Re: Translations of graphs need help
    (Original post by ztibor)
    Generally:
    let y=f(x)
    THen
    Reflection in the y-axis: y=f(-x)
    Reflection in the x-axis:y=-f(x)
    Translating by 'a' parallel to the x: y=f(x-a)
    Translating by 'a' parallel to the y: y=f(x)+a
    Streching by scale factor 'a' parallel to x: y=f(\frac{1}{a}x)
    Streching by scale factor 'a' parallel to y: y=a\cdot f(x)

    F.e for 2nd
    y=sin3x \rightarrow y=sin(-3x)=-sin3x
    for 4th
    y=x^2-4x+1 \rightarrow y=\left (2x)^2-4(2x)+1=4x^2-8x+1
    How can I reflect y=2x^3+x^2-5x+1 into the y-axis?
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