which of the following is a logarithmic function?\n$y = \\log_3x$\n$y = 3^x$\n$y = x + 3$\n$y = x^3$

Brief Explanations:

A logarithmic function has the form $y = \log_a x$ where $a>0,a\neq1$ and $x > 0$. The first option $y=\log_3 x$ is in this form. The second option $y = 3^x$ is an exponential function, the third $y=x + 3$ is a linear function and the fourth $y=x^3$ is a power - function.

Answer:

$y=\log_3 x$