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Question:
Let $f: R \rightarrow R: f(x)=3 x+2$, find $f\{f(x)\}$

Solution:

To find: $f\{f(x)\}$

Formula used: (i) $f$ o $f=f(f(x))$

Given: (i) $f: R \rightarrow R: f(x)=3 x+2$

We have,

$f\{f(x)\}=f(f(x))=f(3 x+2)$

$f \circ f=3(3 x+2)+2$

$=9 x+6+2$

$=9 x+8$

Ans) $f\{f(x)\}=9 x+8$