COLLEGE ALGEBRA

[tena]

I HAVE NEVER SEEN THIS WRITTEN BY ITSELF IN MATH BEFORE. WHAT DOES "WHERE DEFINED MEAN?"

 

[tkhunny]

"where defined" - We're often talking about Real Numbers. I will make that assumption.

[math]y = \dfrac{1}{x}[/math] is not defined at x = 0.

[math]y = \sqrt{x-5}[/math] is not defined for x < 5.

[math]z = \dfrac{5}{x+y}[/math] is not defined for x + y = 0.

 

[Dr.Peterson]

I HAVE NEVER SEEN THIS WRITTEN BY ITSELF IN MATH BEFORE. WHAT DOES "WHERE DEFINED MEAN?"

It will be very helpful if you can show us the entire sentence in which the phrase "where defined" appears. Often definitions depend on context; but more important, we can explain it more fully with a specific example that fits your context.

For one example, we might say that log(x^2) and 2log(x) are equal where both are defined. This means that, for example, 2log(x) is not defined for negative x (or zero); but for any positive value of x, they are equal.

 

[tena]

Where defined X^2-9\X+2\X-3\X-2

 

[tkhunny]

Where defined X^2-9\X+2\X-3\X-2

That's rather difficult to translate. Are those "\"s supposed to be division? Is each additive pair supposed to be grouped?

Perhaps it is written: [math]\dfrac{\dfrac{x^{2}-9}{x+2}}{\dfrac{x-3}{x-2}}[/math]?

Please add parentheses and try to use better notation in order to communicate effectively.

 

[Dr.Peterson]

Where defined X^2-9\X+2\X-3\X-2

This is not a complete sentence, so there is surely more context you can provide. Or is it actually a question, asking "Where [that is, for what values of x] is the following expression [or function] defined?" In that case, it would be asking for the domain.

It will be best if you can show us an image of the page or paragraph where you found this.