# How do you mark/show the critical point (-1, 0) on Nyquist plot? [closed]

I am trying to make the Nyquist plot of the function $\frac{200}{(s+1)(s+2)(s+3)}$ as below. However, I would like to see mark the critical point (-1, 0) on the plot so we can see clearly whether the plot encircles the point or not. I am curious to know how you usually do this? How to show the critical point easily?

NyquistPlot[TransferFunctionModel[200/((s + 1)*(s + 2)*(s + 3)), s]]

## closed as off-topic by C. E., MarcoB, Bob Hanlon, m_goldberg, JensJul 24 '17 at 1:07

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• "This question arises due to a simple mistake such as a trivial syntax error, incorrect capitalization, spelling mistake, or other typographical error and is unlikely to help any future visitors, or else it is easily found in the documentation." – C. E., MarcoB, Bob Hanlon, m_goldberg, Jens
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• You can use the Epilog option: Epilog -> {Red, PointSize[Large], Point[{-1, 0}]} – just add this as the last argument of NyquistPlot. NyquistPlot has all the options that Graphics has. Note that Epilog is documented as an option under Graphics and not under NyqustPlot. It also has its own page in the documentation. – C. E. Jul 23 '17 at 22:39
• Also, you can focus on the critical point with PlotRange, as in: NyquistPlot[TransferFunctionModel[200/((s + 1)*(s + 2)*(s + 3)), s], PlotRange -> {{-5, 1}, {-1, 1}}, Epilog -> {Red, PointSize[Large], Point[{-1, 0}]}] – aardvark2012 Jul 23 '17 at 23:18