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Math Help - standard form

  1. #1
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    standard form

    if you are given the vertex(-3,4) and lets say the information of the parabola is stretched by -2

    i know the vertex form is y=-2(x+3)+4

    but what is the standard form?

    thanks
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  2. #2
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    Quote Originally Posted by william View Post
    if you are given the vertex(-3,4) and lets say the information of the parabola is stretched by -2

    i know the vertex form is y=-2(x+3)+4

    but what is the standard form?

    thanks
    Expand the turning point form.
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  3. #3
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    Quote Originally Posted by mr fantastic View Post
    Expand the turning point form.
    y=-2x-6+4...?
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  4. #4
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    Quote Originally Posted by william View Post
    y=-2x-6+4...?
    Doesn't the equation of a parabola contain a squared term? (I had assumed your original post was missing it due to a typo).
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  5. #5
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    Quote Originally Posted by mr fantastic View Post
    Doesn't the equation of a parabola contain a squared term? (I had assumed your original post was missing it due to a typo).
    y=-2(x+3)^2+4

    you are very right

    y=-2x^2+9x+4...?
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  6. #6
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    Quote Originally Posted by william View Post
    y=-2(x+3)^2+4

    you are very right

    y=-2x^2+9x+4...?
    no.

    (x+3)^2 \neq x^2 + 9
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  7. #7
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    Quote Originally Posted by skeeter View Post
    no.

    (x+3)^2 \neq x^2 + 9
    you're right (x+3)^2=x^2+6x+9 so is it y=-2x^2+6x+9
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  8. #8
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    Quote Originally Posted by william View Post
    you're right (x+3)^2=x^2+6x+9 so is it y=-2x^2+6x+9
    No! Please concentrate on getting the algebra correct. Write out all the steps. Don't take short cuts.

    y=-2(x+3)^2 + 4 = -2(x^2 + 6x + 9) + 4 = -2x^2 - 12x - 18 + 4 = -2x^2 - 12x - 14.
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  9. #9
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    Quote Originally Posted by mr fantastic View Post
    No, Please concentrate on getting the algebra correct. Write out all the steps. Don't take short cuts.

    y=-2(x+3)^2 + 4 = -2(x^2 + 6x + 9) + 4 = -2x^2 - 12x - 18 + 4 = -2x^2 - 12x - 14.
    thanks
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