We need to graph the following function:
[tex]y=\log _{1/2}(x)-4[/tex]
We know that the domain of a logarithmic function can't be negative, then our domain is
[tex]x\in(0,\infty)[/tex]
We need to analyze this function at its extremes to find the asymptotes.
Let's calculate the limit of this function at x = 0 and at infinity.
[tex]\begin{gathered} \lim _{x\to0}\log _{1/2}(x)-4=\infty \\ \lim _{x\to\infty}\log _{1/2}(x)-4=-\infty \end{gathered}[/tex]
By definition, an asymptote of a curve is a line such that the distance between the curve and the line approaches zero as one or both of the x or y coordinates tends to infinity. From our limits, we have an vertical asymptote at x =0 and no horizontal asymptotes.
This logarithmic function, comes from infinity at x = 0, an decays to minus infinity as x grows. We have the following graph: