What is the equation, in standard form, of a parabola that contains the following points? ( -2, -23.5)(0,-4.5)(4,-26.5)

What is the equation, in standard form, of a parabola that contains the following points? ( -2, -23.5)(0,-4.5)(4,-26.5)

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  1. D

    Step-by-step explanation:

    the the 5 minus the 12 and the 0 minus the negative one all finds it way. back to the equation d

  2. -20 = 4a - 2b + c
    -4 = c
    -20 = 16a + 4b + c

    4a - 2b + c = 16a + 4b + c
    4a - 2b = 16a + 4b
    -6b = 12a
    b = -2a

    -20 = 4a - 2b + c
    -20 = 4a + 4a - 4
    -16 = 8a
    -2 = a
    b = 4
    c = -4

    y = -2x^2 + 4x - 4
    y = -2 * (x^2 - 2x) - 4
    y = -2 * (x^2 - 2x + 1 - 1) - 4
    y = -2 * (x^2 - 2x + 1) + 2 - 4
    y = -2 * (x + 1)^2 - 2

  3. Y = -2.5x^2 + 4.5^x + -4.5
    [tex]What is the equation, in standard form, of a parabola that contains the following points? ( -2, -23[/tex]

  4. y = -2*3x - 1

    Step-by-step explanation:

    The first term is -2 and the common ratio is 3 because every term is being multiplied by 3. The equation is y = -2*3x - 1.

  5. The equation of parabola is [tex]y=-\frac{5}{2}x^2+\frac{9}{2}x-4.5[/tex].

    Step-by-step explanation:

    Equation of a parabola is quadratic equation.

    Let the equation of parabola be

    [tex]y=Ax^2+Bx+C[/tex]                  .... (1)

    The parabola contains points ( -2, -23.5), (0,-4.5), (4,-26.5).

    Put (0,-4.5) in equation (1),

    [tex]-4.5=A(0)^2+B(0)+C[/tex]

    [tex]-4.5=C[/tex]

    Put this value in equation (1).

    [tex]y=Ax^2+Bx-4.5[/tex]               ... (2)

    Put  ( -2, -23.5) and  (4,-26.5) in equation (2).

    [tex]-23.5=A(-2)^2+B(-2)-4.5[/tex]

    [tex]-19=4A-2B[/tex]                     .... (3)

    [tex]-26.5=A(4)^2+B(4)-4.5[/tex]

    [tex]-22=16A+4B[/tex]                  .... (4)

    On solving (3) and (4), we get

    [tex]A=-\frac{5}{2}[/tex] and [tex]B=\frac{9}{2}[/tex]

    Therefore the value of parabola is

    [tex]y=-\frac{5}{2}x^2+\frac{9}{2}x-4.5[/tex]

    [tex]What is the equation, in standard form, of a parabola that contains the following points? ( -2, -23[/tex]

  6. C) y=x^2-2x+6

    Step-by-step explanation:

    We are given three points

    (1,5) (-1,9) and (4,14)

    We can verify each options

    option-A:

    [tex]y=x^2+6x+2[/tex]

    we will verify each points

    At (1,5):

    we can plug x=1 and check whether y=5

    [tex]y=(1)^2+6(1)+2[/tex]

    [tex]y=9[/tex]

    It does not satisfy point

    So, this is FALSE

    option-B:

    [tex]y=x^2+6x-2[/tex]

    we will verify each points

    At (1,5):

    we can plug x=1 and check whether y=5

    [tex]y=(1)^2+6(1)-2[/tex]

    [tex]y=5[/tex]

    It satisfies point

    At (-1,9):

    we can plug x=-1 and check whether y=9

    [tex]y=(-1)^2+6(-1)-2[/tex]

    [tex]y=-7[/tex]

    It does not satisfy point

    So, this is FALSE

    option-C:

    [tex]y=x^2-2x+6[/tex]

    we will verify each points

    At (1,5):

    we can plug x=1 and check whether y=5

    [tex]y=(1)^2-2(1)+6[/tex]

    [tex]y=5[/tex]

    It satisfies point

    At (-1,9):

    we can plug x=-1 and check whether y=9

    [tex]y=(-1)^2-2(-1)+6[/tex]

    [tex]y=9[/tex]

    So, it satisfies point

    At (4,14):

    we can plug x=4 and check whether y=14

    [tex]y=(4)^2-2(4)+6[/tex]

    [tex]y=14[/tex]

    So, it satisfies point

    so, this is TRUE

  7.   C)  y = -2x^2 +4x - 4

    Step-by-step explanation:

    The y-values are the same for points (-2, -20) and (4, -20), so the axis of symmetry is halfway between those points, at x = (-2+4)/2 = 1.

    The y-intercept is (0, -4), so the only viable answer choices are B and C. The axis of symmetry is given by ...

      x = -b/(2a)

    For choice B, this is x = -4/(2(-1)) = 2 (doesn't work).

    For choice C, this is x = -4/(2(-2)) = 1, which matches the above analysis.

    The appropriate choice is ...

      y = -2x^2 +4x - 4

    _____

    Alternate solution

    If you like, you can derive the equation for the parabola. Since you know that the y-intercept is -4, you can write the equation as ...

      y = ax² +bx -4

    Filling in the data points that are not x=0, we have two equations in two unknowns:

      -20 = a(-2)² +b(-2) -4   ⇒   4a -2b = -16

      -20 = a(4)² + b(4) -4    ⇒   16a +4b = -16

    Adding twice the first equation to the second gives ...

      2(4a -2b) + (16a +4b) = 2(-16) +(-16)

      24a = -48

      a = -2 . . . . . . . . matches choice C

      4(-2) -2b = -16 . . . . . substitute into an equation to find b

      -2b = -8 . . . . . . . . . . add 8

      b = 4 . . . . . . . . . . . . . divide by -2

    The equation that fits the given data is ...

      y = -2x² +4x -4

    [tex]What is the equation, in standard form, of a parabola that contains the following points? (-2, -20)[/tex]

  8.   f(x) = x² -3x +2

    Step-by-step explanation:

    We know from the first point that (x -2) is a factor of the polynomial, so we can write the other factor as (ax+b). Filling in the values from the other two given points, we have ...

      f(x) = (x -2)(ax +b)

      f(3) = (3 -2)(3a +b) = 2

      f(4) = (4 -2)(4a +b) = 6

    __

    From the first of these, ...

      3a + b = 2

    Dividing the second by 2, we have ...

      4a + b = 3

    Subtracting the first of these equations from the second gives ...

      (4a +b) -(3a +b) = (3) -(2)

      a = 1

    Using this in the first of the above equations, we have ...

      3·1 + b = 2

      b = -1

    Then the factored form of the equation is ...

      f(x) = (x -2)(x -1)

    Expanding this to standard form, we have ...

      f(x) = x² -3x +2

    [tex]What is the equation, in standard form, of a parabola that contains the following points? (2,0), (3[/tex]

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