how to calculate the natural domain of 1/x+9 ?

Question

anonymous · Answer

do you mean y = 1/(x+9)  ?

anonymous · Answer

yeah

anonymous · Answer

sry about that

anonymous · Answer

no problem, so for a problem like this, you need to set the denominator (bottom part) of the fraction to 0, because that's where the function is undefined (you can't divide by zero). x+9=0, so x = -9, so the natural domain is all real numbers except -9. in math notation, this would be (-infinity, -9) U (-9, infinity). the parentheses mean that -9 is not included (brackets would mean that it is included, and the convention is that "we never quite reach infinity"). the U means "union", meaning that the domain is the combination of every value in either set of numbers. let me know if you have any questions.

anonymous · Answer

thank you so much!

anonymous · Answer

i got one more question, anyone there?

anonymous · Answer

hey, i'm still here. what's up?

anonymous · Answer

hey, its just a easy exercise on absolute value

anonymous · Answer

http://www.twiddla.com/499656 there's a whiteboard there, its easier for me to explain