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Math Help - How to solve inverse function?

  1. #1
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    How to solve inverse function?

    Find a formula f-1(x). Give the domain of f-1, including any restrictions "inherited" from f
    So one of my problem is f(x)=3x-6

    But I'm kind of confused on how to start off
    At first I thought it was like having the equation all go to the power of -1
    So I got y=(1/3)x-(1/6)

    But in the answer book it says: y=(1/3)x + 2
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  2. #2
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    Re: How to solve inverse function?

    Quote Originally Posted by Chaim View Post
    Find a formula f-1(x). Give the domain of f-1, including any restrictions "inherited" from f
    So one of my problem is f(x)=3x-6, answer book it says: y=(1/3)x + 2
    Start with x=3y-6. Solve for y.
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  3. #3
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    Re: How to solve inverse function?

    Quote Originally Posted by Plato View Post
    Start with x=3y-6. Solve for y.
    x = 3y - 6
    x - 6 = 3y
    (x/3) - 2 = y

    Oh!
    Now I see!
    Thanks!
    So that means the inverse really means solving for 'y' when you have 'x' as a single
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  4. #4
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    Re: How to solve inverse function?

    Quote Originally Posted by Chaim View Post
    x = 3y - 6
    x - 6 = 3y
    (x/3) - 2 = y

    Oh!
    Now I see!
    Thanks!
    So that means the inverse really means solving for 'y' when you have 'x' as a single
    Finding the inverse function (not the "reciprocal" which is 1/f) for any function means swapping x and y and then solving for y. It is, strictly speaking, the swapping of x to y that gives the inverse function but we always want a function written in the form y= f(x) so we always want to solve for y.
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  5. #5
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    Re: How to solve inverse function?

    Quote Originally Posted by HallsofIvy View Post
    Finding the inverse function (not the "reciprocal" which is 1/f) for any function means swapping x and y and then solving for y. It is, strictly speaking, the swapping of x to y that gives the inverse function but we always want a function written in the form y= f(x) so we always want to solve for y.
    Oh!
    Ok thanks!
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