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If \( f(x)=x+7\: and \: g(x)=x-7, x \in R\) find fog(7).

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  • Given two functions $f:A \to B $ and $g:B \to C$, then composition of $f$ and $g$, $gof:A \to C$ by $ gof (x)=g(f(x))\;for\; all \;x \in A$
  • Given two functions $g:A \to B $ and $f:B \to C$, then composition of $g$ and $g$, $fog:A \to C$ by $ fog (x)=f(g(x))\;for\; all \;x \in A$
Given : $f(x)=x+7$
$g(x)=x-7$
$\therefore$ fog=$(x-7)+7$
$\Rightarrow x$
$fog(7)=7$
answered Oct 2, 2013 by sreemathi.v
 
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