Question

O domínio da função f (x)=raiz de x+3+1/x?

Answer 1

Se for f (x)= $\sqrt{ x+3+ \frac{1}{x} }$

x+3+$\frac{1}{x} \geq 0$

$\frac{x^2+3x+1}{x}$≥0

q=x²+3x+1
raízes (3-√5)/2  e (-3-√5)/2
(-3-√5)/2 ≤ x ≤(3-√5)/2 

p=x   ==> R - {0}  

Estudo de sinais
q++++++++++(-3-√5)/2-----------------(-3+√5)/2+++++
p+++++++++++++++++++++0++++++++++++++++
p/q++++++++(-3-√5)/2--------(0)------(-3-√5)/2+++++++

Domínio
[-∞,(-3-√5)/2] U [(-3-√5)/2,+∞)