Question

Explicite o domínio das funções reais definidas por:
b) f(x)= x/x²-9
c) f(x)= x²+1
d) f(x)= raiz ² x-7

Answer 1

$Ola'! \\ \\ \boxed{a} \\ \\ f(x)= \frac{x}{ x^{2} -9} ~~, com~restric\~ao~em~que~[x\²-9 \neq 0] \\ \\ x^{2} -9 \neq 0 \\ \\ x^{2} \neq 9 \\ \\ x \neq \pm3 \\ \\ ent\~ao~\mathbb{ID}=\mathbb{IR}-\{\pm3\}$
$====================================== \\\boxed{b} \\ \\ f(x)= x^{2} +1 \\ \\ por~tanto~o~dominio~e': \\ \mathbb{D}=R \\ \\ ====================================== \\ \boxed{c} \\ \\ f(x)= \sqrt{x-7} ~~~--\ \textgreater \ com~retric\~ao~onde~[x-7 \geq 0] \\ \\ x-7 \geq 0 \\ \\ \boxed{x \geq 7}\\ \\ \mathbb{D}=\{x~ E~\mathbb{IR}/ x \geq 7\}~ \\ \\ \\ bons~estudos!$