## anonymous one year ago Identify the excluded value for the rational function. y=4x-1 PLEASE help me understand this!!!

1. SolomonZelman

this function here, that you posted is a polynomial

2. SolomonZelman

that function includes any x-value in it's domain. It is continuous over $$(-\infty,~+\infty)$$

3. SolomonZelman

there are no excluded x values in a polynomial.

4. anonymous

Are you sure because I have already tried answering this and I put 0, and it says that i'm wrong. The options are: 0, 1, 2, and 3.

5. SolomonZelman

you put y=4x-1, you see that, correct?

6. SolomonZelman

maybe it is $$\large\color{black}{ \displaystyle y=\frac{\rm something}{\rm another~~something } }$$

7. anonymous

ya it's y=4/x-1

8. SolomonZelman

oh, $$\large\color{black}{ \displaystyle y=\frac{4}{x-1} }$$

9. SolomonZelman

that is much better:)

10. SolomonZelman

what number can't you divide by, do you know?

11. anonymous

x?

12. SolomonZelman

4 ÷ what = undefined or indeterminate ?

13. SolomonZelman

you can divide by 1, you can divide by 3, you can divide by -0.0003, but you can NOT divide by 0. right?

14. SolomonZelman

you can divide by anything, but not by 0

15. anonymous

right

16. SolomonZelman

so, in your function $$\large\color{black}{ \displaystyle y=\frac{4}{x-1} }$$ , there is one x-value that will not give you an adequate output, because you would need to divide by 0.

17. SolomonZelman

you are dividing by x-1. so, when (for what x-value) is this the same as dividing by 0 ?

18. SolomonZelman

(in other words, when "x-1" is equivalent to 0? when x=what ?)

19. anonymous

undefined?

20. SolomonZelman

ok, lets go about it in a different way...

21. SolomonZelman

you can't divde by 0, you know that?

22. anonymous

yes

23. SolomonZelman

in our case we are dividing 4 by "x-1", yes?

24. SolomonZelman

now, when dividing by x-1, is going to be the same thing as dividing by 0, that will give us an undefined result.

25. SolomonZelman

dividing by x-1 is same as dividing by 0, when x-1 is same as 0. there is one x-value for which x-1 is same as 0. x-1=0 when is x-1=0?

26. anonymous

idk

27. SolomonZelman

I tried my best, I apologize, but I don't think I can help you more. I am capable of you the answer, but I am not going to.

28. SolomonZelman

of giving you*

29. SolomonZelman

bye

30. anonymous

Well thanks anyway

31. SolomonZelman

-;( yw

32. anonymous

@SolomonZelman I think I am understanding this more. x-1=0 is 1-1=0 is this correct?

33. anonymous

So this would mean that the excluded value is 1 right? @SolomonZelman

34. SolomonZelman

yes, yes very good!

35. SolomonZelman

the excluded value is 1. x≠1

36. SolomonZelman

:)

37. anonymous

Thank you so much for helping!!