jmc

After reflecting the point $(3,4)$ in the $x$-axis, the $x$-coordinate of the image will be the same as the $x$-coordinate of the original point, $x=3.$ The original point is a distance of $4$ from the $x$-axis. The image will be the same distance from the $x$-axis, but below the $x$-axis. Thus, the image has $y$-coordinate $-4.$ The coordinates of the image point are $\boxed{(3,-4)}.$