Explanation:
a)
Looking at the graph, it is reasonable to assume that after 3 hours, the concentration should be about 1.5 miligrams per liter.
b)
[tex]\begin{gathered} We\text{ will subsitute t =3 into the equation:} \\ y\text{ = }\frac{5(3)}{3^2+1} \\ \text{ =1.5} \end{gathered}[/tex]
Answer: Concentration = 1.5 miligrams per liter after three hours.
c)
The function is given by a term in the numerator and a term in the denominator. The term in the denominator cannot equal 0.
[tex]\begin{gathered} x^2+1\ne0 \\ But,\text{ x}^2\text{ will never be negative and the function cannot y cannot go below 0.} \end{gathered}[/tex]
Answer: The horizontal asymptote is the line y = 0