You use KhanAcademy! I find them a maze of information: it's difficult to find the right bit, but once you found it, it's valuable all right!
The domain are the values your function can assume. For a linear equation, you can imagine that any x value is valid: All real values of t are viable options to stuff into your equation without there being a contradiction or a mathematical impossibility.
Consider f(x) = 1/(x+3)
One cannot divide by zero, therefore x may never equal -3. Your domain would be all real values of x except for x = -3.
This goes for any division: your denominator may not equal zero. If there is a value for x where this is the case, it will be the value that is not in your domain.
Similarly, you know log functions cannot have 0 or a negative number and squareroots won't work well with negative numbers.
/e You'll find horizontal asymptotes by simply stuffing in a silly big x value and see where your answer is going to. For slant asymptotes you need polynomial divisions, but from the looks of your exercise I don't think it's relevant as of yet. If it is, you can find it here:
http://www.purplemath.com/modules/asymtote3.htmThe domain of a function is determined by values for the variable that a function is not allowed to assume.
This post was edited by Forg0tten on May 28 2017 02:34pm