What does this mean when talking about suitable domains?

>>7763411
It means x is real.

>>7763411
x = variable x
∈ = 'is an element of'
R = real number set
Hence, x∈R is simply a small note stating that x is a real number.

>>7763412
So how big do I need to make this graph?

>>7763417
not that big, just - to + infinity

>>7763411
It means x is not fake

>>7763571
u mean 'irrational'

>>7763771
Irrational numbers are still real. They're literally between reals

>>7763411
X is an element of the real numbers

Here, have a video:
https://youtu.be/dLn5H69lS0w?t=34

It means your 'x's cameltoe is real.

can't you read the picture? it says

boobs, vagina, penor in hole

>>7763775
You mean rationals?

>>7763818
>>7763818
Yes. I am an idiot and English is not my first language

>>7763818
>>7763827
they are between reals as well ;^)

>>7763831
>>7763818
>>7763771
Stop being so irrational

It means x is not imaginary, in which case you'd need another dimension to your graph.

>>7763422
>>7763417
Just scale your axis by the tan(x) and you only have to draw from -pi/2 to +pi/2