Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

FIND f(g(x)) and g(f(x)) and determine wether the pair of functions f and g are inverses of each other?

f(x)=7x-4 and g(x)=x+7/4

a. f(g(x))=

Simplify answer

2 Answers

Relevance
  • Juan
    Lv 6
    8 years ago
    Favorite Answer

    f(x) = 7x - 4

    g(x) = x + (7/4)

    f(g(x)) just means plug [x + (7/4)] where their is

    an x in the f function therefore

    f(g(x)) = 7[x + (7/4)] - 4

    7x + (49/4) - (4)

    7x + (49/4) - (16/4)

    7x + (33/4)

    g(f(x)) just means plug (7x - 4) where their is

    an x in the g function therefore

    g(f(x)) = (7x - 4) + (7/4)

    7x - (16/4) + (7/4)

    7x - (9/4)

    To find if there inverse make

    one of the equations set to the answer y

    y = 7x + (33/4)

    now switch the variable

    x = 7y + (33/4)

    solve for y

    x = 7y + (33/4)

    x - (33/4) = 7y

    y = (x/7) - (33/28)

    There not inverse functions of each other

  • chump
    Lv 5
    8 years ago

    f(g(x)) 〓 7(x+7/4) - 4 〓 [(7x + 49)/4] - 4

    g(f(x)) 〓 (7x-4+7)/4 〓 (7x+3)/4

    The inverse of y 〓 7x - 4 is defined as x 〓 7y - 4 and isolating y produces y 〓 (x+4)/7 which is not g(x).

    If the fuctions were inverses then f(g(x)) 〓 g(f(x)) 〓 1.

Still have questions? Get your answers by asking now.