The function $f$ and the composite function $fg$ are defined as $f:x\mapsto x+2$ , $fg:x\mapsto 3x-2$. Find the function $g$.
I just started learning functions and need help with it. Please provide workings so that I understand better, thank you.
Asked
Active
Viewed 189 times
1 Answers
1
$$f(x)=x+2 \rightarrow f(g(x))=g(x)+2 $$
but
$$f(g(x))=3x-2$$
so
$$g(x)+2=3x-2 \rightarrow g(x)=3x-4$$
Arnaldo
- 21,342
-
why is $f(g(x))=3x-2$ and not $3x+2$ – user407406 Jan 16 '17 at 14:49
-
1@user407406, because that is what you wrote. – Ennar Jan 16 '17 at 14:49
-
oh yeah, my bad – user407406 Jan 16 '17 at 14:50