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# Loci in argand diagrams help watch

1. I can plot them perfectly fine, but when you have to plot the circls and then it asks 'write down the minimum or maximum value of arg z' im completely lost.
Here is an example if anyone is willing to walk me through how to do it
P represents a complex number Z on an argand diagram. Given that (modulus) Z+2-2root3i(end modulus)=2 Write down the minimum and maximum value of arg Z

All help is appreciated
2. So if you have sketched it correctly it's a circle centre (-2,2sqrt3) radius 2. To find max and min value of argz draw lines that are tangent to the circle from the origin and then draw a radius to the tangent. You should have a right angle triangle so just use basic trigonometry to find angles required - if you have followed this as I intended then it should be quite straight forward.
3. so if you have a circle the biggest angles that you can get from the origin are when you draw tangent lines:

like this but on the opposite side...

https://i.stack.imgur.com/VAFO0.png
4. (Original post by B_9710)
So if you have sketched it correctly it's a circle centre (-2,2sqrt3) radius 2. To find max and min value of argz draw lines that are tangent to the circle from the origin and then draw a radius to the tangent. You should have a right angle triangle so just use basic trigonometry to find angles required - if you have followed this as I intended then it should be quite straight forward.
I have got this circle but i cant get the right value, im so confused : (((

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