Maths symbol? (1 Viewer)

[cloud edwards]

Hey, attached is from a maths textbook. THere's this 'R' looking symbol that i haven't seen before. What does it mean and how is it typically used.

Thanks

 

[captainhelium]

I think that just means 'Real Numbers'.

It's mainly just used as a restriction or as some extra info to a question I think such as saying that 'x' is/can only a real number.

 

[HeroWise]

IT means in reals, its just limiting the numbers in the real system aka not being able to take roots of imaginary

 

[fan96]

As everyone else said, it's set notation for all real numbers.

Real numbers include integers, rationals and irrationals such as , but stop short of including imaginary numbers like .

Sometimes it will be written , which means the same thing.

Here are some other ones that you may encounter:

(natural numbers)

(integers)

(rationals)

(complex numbers)

You can also add a superscripted sign to place further restrictions.

e.g. means positive integers.

 

[cloud edwards]

Ohhh thanks