## korosh23 one year ago Calculus 12 Question! Please explain the part I highlighted. Thank you. Wait for the attachment to load

1. korosh23

2. korosh23

There is the solution to the answer, but I don't understand it. Could you please explain?

3. anonymous

When the x makes the denominator 0, it is not included in the domain. $\frac{ 1 }{ x(x-1) }$

4. anonymous

x=? makes it zero.

5. anonymous

and x=1

6. anonymous

i think the explanation you need might be just that $(-\infty, 0)\cup (0,1)\cup (1,\infty)$ is just a really long winded way of saying all numbers except $$0$$ and$$1$$

7. korosh23

yes x-1=0 x=1

8. anonymous

1(1-1)=0

9. korosh23

@satellite73 right, but I don't understand how? the way it is written is confusing

10. korosh23

@shalante I am following you. Go ahead

11. anonymous

$(-\infty,0)$ means $x <0$

12. anonymous

meaning x can 0.0001 or -0.0001 but not at 0

13. anonymous

(0,1) means it can be from 0.0001 to 0.9999 but not at 1 or 0

14. anonymous

$(1,\infty)$ means it can be from 1.0001 to infinity.

15. korosh23

Ok and what does the U shape represent?

16. anonymous

only 0 and 1 makes it undefined So we wont include $x \le0$ or $x \le 1$ U is just a set of interval

17. anonymous

A gap between undefined values.

18. korosh23

But in this case it has to be x cannot equal those numbers. Since any number less or more than those would be defined. Am I right?

19. korosh23

@Shalante, one more question. If something is like x cannot equal 1, can we say the npvs or non permissible values are 1

20. anonymous

For the domain?

21. korosh23

Yes I believe. Like saying x cannot equal 1. So npvs of x are 1. IS it correct?

22. anonymous

Domain has to be an interval of defined value

23. anonymous

If it asks you for vertical asymptote, it would work.

24. zepdrix

npv's? Hmm ive never heard that before :) interesting

25. korosh23

Yes it was in my pre-cal 11 textbook. lol

26. korosh23

@zepdrix and @Shalante, I am fine with solving questions, but my main problem now is understnading important concepts. Can I tag you in other questions to explain something like this. If it is ok with you guys?

27. anonymous

Yep, the name is interesting. Havent heard it in a while.

28. anonymous

Now I want a break and play. If no one does, I will. (In like 20 minutes)

29. korosh23

Ok thanks for help.

30. zepdrix

I don't think it was mentioned earlier, just want to add, U means union. It's like.. the sum of those intervals, is your domain|dw:1443234023659:dw|x can lie anywhere in the ( brackets .