Algebra

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Given f(x)=-4+lnx; Find the inverse of f. f^-1=?

  • Algebra -

    original:
    y = 4 + lnx
    inverse:
    x = 4 + lny
    solving for y
    lny = x-4
    y = e^(x-4)

    f^-1 (x) = e^(x-4)

  • Algebra -

    How do you find the domain and range?

  • Algebra -

    domain is your choice of x's that you can use in your equation
    For logs, one of the main properties is that I can only take the log of a positive number

    so for y = 4 + lnx , the domain is x > 0
    however, the result of taking such logs results in any real number, so the range is y ∈ R

    After taking the inverse of a function, the domain of the original becomes the range of the inverse, and the range of the original becomes the domain of the inverse.

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