How to mark a point on a graph?

So I’m obtaining the following graph:

graphicDelayZOOM =   LogLinearPlot[GroupDelay /. w -> 2 \[Pi] f, {f, 10, 3000},    PlotRange -> {{100, 3000}, {0.000116, 0.0001201}},    PlotPoints -> 200,    PlotStyle -> {{AbsoluteThickness[1.5], RGBColor[1, 0, 0]}},    GridLines -> Automatic, FrameLabel -> {"f(Hz)", "time"},    Frame -> True, BaseStyle -> {FontFamily -> "Times", FontSize -> 12}] 

enter image description here

Now I want to display the point f1=2000, GroupDelay(f1). Is there any easy way to do it?