View Full Version : Maths Question about Braces ({[]})

Davros

09-30-2004, 07:58 PM

Hi there,

What is the proper distinction between the different brace/parenthesis notations:

{}

[]

()

when used in math (not programming)?

Perspective

09-30-2004, 08:02 PM

This depends on how they are used. here are some common ones

{} - used for set theory ex. { x | f(x) < 4 }

() - used for function notation as shown above f(x)

() - used for order of operations ex. (3 - x) * ( (x / 2) / y )

() [] - used for exclusive/inclusive intervals ex. [3, 6) Three to six including 3 but not 6

etc...

Davros

09-30-2004, 08:06 PM

Good stuff. Thanks.

ZakkWylde969

09-30-2004, 09:04 PM

() [] - used for exclusive/inclusive intervals ex. [3, 6) Three to six including 3 but not 6

etc...

Are you talking about arrays?

:confused:

KneeGrow

09-30-2004, 09:12 PM

Are you talking about arrays?

:confused:

No no, what he means is that if you have a graph of like a Domain or Range you write

[-5, 3) that means all numbers work from -5 to 3 but 3 is not included so basically everything between -5 to 2.999999999999

ZakkWylde969

09-30-2004, 09:15 PM

Oh ok. That's really cool actually. No longer will I have to write everything then add another

x =/= #

[] also used for evaluating integrals with the limits writen in the upper and lower corner of the "]" - I've seen some text books do it.

Zach L.

09-30-2004, 10:40 PM

[] are occasionally used for () in order-of-ops for clarity reasons (I do this often). E.g. ([4x * (3 - 2x)] / 6). I've never seen {} used that way, though. Also, {} is sometimes used for series notation. E.g. {a^i} with a lower limit on the bottom corner of the '}' and an upper limit on the '}' (if applicable).

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