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    • Thread Starter

    ok, quick question...


    f(x) = 2x + 1
    g(x) = x^2
    h(x) = 1 / x

    a) find expressions for fg(x) and gf(x)

    I got fg(x) = 2x^2 + 1 and gf(x) = 4x^2 + 4x + 2

    are these right? if they are I need to:

    b) hence find all values of x for which fg(x) = gf(x)

    For some reason when i did this I got a strange answer, so its probably wrong.

    and finally.

    c) show gh(x) = hg(x) for all values of x except x = 0

    can anyone help?

    gf(x) = 4x^2 + 4x + 1

    0 = gf(x) - fg(x) = 2x^2 + 4x
    x = 0, -2

    gh(x) = (1/x)^2 = 1/x * 1/x = 1/x^2 = hg(x)
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Updated: March 15, 2004

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