# binary

• October 10th 2012, 09:42 AM
franios
binary
Not sure what they are asking:

Provide an interpretation of the statement in the context of functions:
The binary operations multiplication and division of real numbers are inverse operations.
• October 10th 2012, 10:41 AM
johnsomeone
Re: binary
The idea they're after is from this observation:
Divide by 3, then multiply by 3, and you're back where you started.
Divide by $4\pi$, then multiply by $4\pi$, and you're back where you started.
Multiply by $-15$, then divide by $-15$, and you're back where you started.
Multiply by $-4+3\sqrt{7}$, then divide by $-4+3\sqrt{7}$, and you're back where you started.
Etc.
• October 10th 2012, 11:05 AM
emakarov
Re: binary
Quote:

Originally Posted by franios
Not sure what they are asking:

Provide an interpretation of the statement in the context of functions:
The binary operations multiplication and division of real numbers are inverse operations.

Multiplication and division signs are usually written between numbers, but multiplication and division are just binary functions that can be denoted, for example, by m(x, y) and d(x, y). My guess is the question asks you to formally write the statement "multiplication and division are inverse operations" using this notation. Though if this problem comes from a textbook, it would help to look at the discussion and other problems in the corresponding section. For example, there is probably a discussion of inverse functions, which lists definitions and notations that you are expected to use.