# Thread: Help with combination and composition of functions

1. ## Help with combination and composition of functions

let f(x) = 1/x+1 and g(x) = sqrt x+2
find the domain of:

• f
• g
• f + g
• f/g

2. $f(x)=\frac1{x+1}$

This function is well defined $\forall x\in\mathbb R-\{-1\}$

$g(x)=\sqrt{x+2}$

This function is well defined $\forall x\ge-2\,\because\,x+2\ge0$

--

I don't see composition of functions in the last two options. May be you wanna compute something like $(f\circ g)(x)$?