Question

-4 is undefined for (fºg)(x).Reason: g(-4) =which is undefined for f.

Answer 1

Consider the given composite function,

$f\circ g(x)=\frac{1}{x+4}$

Clearly, the composite function is undefined for the value x = - 4.

It is because at this value the denomainator of the rational function becomes zero, which makes the fraction indeterminate.

Given the function,

$g(x)=x+4$

Substitute x = - 4,

$\begin{gathered} g(-4)=-4+4 \\ g(-4)=0 \end{gathered}$

Thus, the required value is 0.