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Math Help - Is this work correct?

  1. #1
    Senior Member Danneedshelp's Avatar
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    Is this work correct?

    f(x)=tan(x*pi/2)

    Solving for y: x=tan(y*pi/2) then, y=2/p1*(arctan(x))

    so, lets now let g(x)=2/p1*(arctan(x))

    g(f(x))=g(tan(x*pi/2))=2/p1*(arctan(tan(x*pi/2))=x

    f(g(x))=f(2/pi*(arctan(x))=tan((2/pi*arctan(x))*pi/2)=x

    Sorry, the notation is messy. Basically I'm just trying to find the compositions of f(x) and g(x). So, g o f and f o g. I have gone blank on my trig and my calc is giving me all kinds of wierd results.

    Thanks.
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  2. #2
    MHF Contributor
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    Quote Originally Posted by Danneedshelp View Post
    f(x)=tan(x*pi/2)

    Solving for y: x=tan(y*pi/2) then, y=2/p1*(arctan(x))

    so, lets now let g(x)=2/p1*(arctan(x))

    g(f(x))=g(tan(x*pi/2))=2/p1*(arctan(tan(x*pi/2))=x

    f(g(x))=f(2/pi*(arctan(x))=tan((2/pi*arctan(x))*pi/2)=x

    Sorry, the notation is messy. Basically I'm just trying to find the compositions of f(x) and g(x). So, g o f and f o g. I have gone blank on my trig and my calc is giving me all kinds of wierd results.

    Thanks.
    Your working is a bit all over the place.

    First - what is it you're trying to do?
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