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Find the formula for an exponential function that passes through the two points given. Please show work. (-1,3/4) and (3,192)?

3 Answers

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  • 2 years ago
    Favorite Answer

    The exponential function is: y = abˣ

    where b > 0

    When x = -1, y = 3/4:

    3/4 = ab⁻¹

    ab⁻¹ = 3/4 …… [1]

    When x = 3, y = 192:

    192 = ab³

    ab³ = 192 …… [2]

    [2]/[1]: b⁴ = 256

    b = 4

    Substitute b = 4 into [2]:

    a * 4³ = 192

    64a = 192

    a= 3

    The exponential function is: y = 3 * 4ˣ

  • Anonymous
    1 year ago

    I don't know.................

  • 2 years ago

    you have only 2 points, so there are an infinite number of solutions, and a straight line or other curves also are solutions.

    try y = Ax² + B

    plug in the numbers, solve for A and B

    y = Ax² + B

    3/4 = A + B

    192 = 9A + B

    subtract

    191.25 = 8A

    A = 23.90625

    B = 0.75–23.90625 = –23.15625

    so equation is

    y = 23.90625 x² – 23.15625

    check

    x = –1

    y = 0.75

    x = 3

    y = 192

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