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?

What is the point of origin for a square area of effect?

The spellcasting rules for areas of effect state:

A spell’s description specifies its area of effect, which typically has one of five different shapes: cone, cube, cylinder, line, or sphere. Every area of effect has a point of origin, a location from which the spell’s energy erupts. The rules for each shape specify how you position its point of origin. Typically, a point of origin is a point in space, but some spells have an area whose origin is a creature or an object.

A spell’s effect expands in straight lines from the point of origin. If no unblocked straight line extends from the point of origin to a location within the area of effect, that location isn’t included in the spell’s area. To block one of these imaginary lines, an obstruction must provide total cover.

Notably, square is not one of the shapes defined, yet there exist several spells which have a square area of effect, such as entangle or Evard’s black tentacles.

The spell grease tells us in its description:

Slick grease covers the ground in a 10-foot square centered on a point within range.

But this clarification is not present in the descriptions of entangle and Evard’s black tentacles.

So what is the point of origin of a square area of effect when it is not specified in the spell description?

Does “a point you choose” include any movable surface?

I read somewhere that spells like Darkness and Silence, where the effect of the spell spreads from a point I choose within range, can be cast on the surface of a moveable item. But after extensive googling, I couldn’t find confirmation on it anymore. These are the relevant parts of the spell descriptions:

Darkness
Magical darkness spreads from a point you choose within range to fill a 15-foot radius sphere for the duration. …

Silence
For the duration, no sound can be created within or pass through a 20-foot-radius sphere centered on a point you choose within range. …

So theoretically, does this mean that a Warlock with the Devil’s Sight incantation can cast Darkness on their armor and "carry" it around with him? Giving him semi-permanent (Concentration) advantage to targets without Devil’s Sight/Truesight?

Another example would be someone casting Silence on an enemy mage, rendering them unable to cast spells with Verbal components also semi-permanently (Concentration)?

If a paladin becomes Large, at what point does the paladin’s aura originate?

If you enlarge a paladin (so that they take up 2×2 squares on a grid), what point does their aura’s radius start at?

For Medium/Small creatures (who take up a 1×1 square on a grid), it radiates from one of the corners of the square. For Large creatures, is it still at one of the corners of the 2×2 square, at the intersection at the center of one of the sides of the creature’s space, or at the intersection at the center of the creature’s space?

Additional info:

  • According to the designers, the point of origin of a spherical area of effect is at the intersection of squares on a grid.
  • According to Mike Mearls, paladin auras work the same way.

Can a player spend a fate point to declare it a full moon?

Is a player able to spend a fate point, to declare it a full moon? For instance, if they have a lycanthrope character who gains more power in the full moon.

I know a fate point can be spent to declare an arrival/having an item and such like that, which is unrelated to an aspect and more setting related. Would this "it’s a full moon tonight" also be permissible to try to declare under the official rules as they are written?

Or is it too much to do with the broader setting, as opposed to an individual character, making it GM only control and decision?

What is the point of lowering the hood on a hooded lantern?

From the PHB, p. 152:

Lantern, Hooded. A hooded lantern casts bright light in a 30-foot radius and dim light for an additional 30 feet. Once lit, it burns for 6 hours on a flask (1 pint) of oil. As an action, you can lower the hood, reducing the light to dim light in a 5-foot radius.

PHB errata says that you are not supposed to be “blinded by darkness”, but can’t see anything that is concealed by the darkness:

Vision and Light (p. 183). A heavily obscured area doesn’t blind you, but you are effectively blinded when you try to see something obscured by it.

But when you are in the darkness yourself, you can see things that are not. That means that a hooded lamp will be visible, since it still creates a lit area around.

Assuming that your foes will see the light at any range regardless, what is the point of reducing the lit area?

Wares Point

Why are you selling this site?
I am not a marketing guru, I'm a programmer who picked the site up to make some extra money and I do not want to prioritize learning scaling & marketing on top of what I'm already doing and loving. A hobby that turned into a business I won't be able to manage.

How is it monetized?
Ads are strictly ran through Facebook Ads.

Does this site come with any social media accounts?
I'd be 100% willing to transfer over any social account directly…

Wares Point

Is there any point in using PGP or S/MIME when your receipients mostly don’t use it?

For an average company how much does it make sense to implement S/MIME or PGP for providing their E-mails the verification functionality (please correct me if I’m wrong), which most E-mail clients to my best of knowledge support, even though the contacts of the company usually don’t use any kind of E-mail encryption.