Question

find domain of f(x)= \frac{\sqrt{1 + x}}{9 - x}

Answer 1

\[f \left( x \right)=\frac{ \sqrt{1+x} }{ 9-x }\]
for domain \[x+1\ge0,x \ge -1\]
\[9-x \neq 0,9 \neq x~or x \neq 9\]
domain is [-1,9) U (9, infinity )