## burhan101 Group Title limit one year ago one year ago

1. burhan101 Group Title

$\lim_{x \rightarrow -1} \sqrt{\frac{ 1-t^2 }{ 1+t }}$

2. kphilips2010 Group Title

why is your limit has x approahing -1 and the function is in terms of t?

3. burhan101 Group Title

that was a typo an my behalf :\$

4. kphilips2010 Group Title

factor the numerator to (1+t)(1-t) then cancel the (1+t) out so you are left with $\sqrt{1-t}$

5. kphilips2010 Group Title

then you can substitue

6. burhan101 Group Title

@kphilips2010 that method is not correct

7. burhan101 Group Title

i dont think i ca use conjugates for this question

8. kphilips2010 Group Title

why is that wrong?

9. burhan101 Group Title

because it's not a binomia

10. burhan101 Group Title

binomial*

11. kphilips2010 Group Title

12. kphilips2010 Group Title

I didnt say it was a binomial, I am saying you can factor the binomial into (1+t)(1-t)

13. burhan101 Group Title

but isnt there another method, like multiply by the denominator or something of the like

14. kphilips2010 Group Title

no not in this case

15. kphilips2010 Group Title

LOL i am sure I am right...I hope

16. joemath314159 Group Title

kphilips method is good imo.

17. kphilips2010 Group Title

thanks joemath314159

18. burhan101 Group Title

i know thats how i approached the question at first but my teacher said this method was wrong ? :S

19. kphilips2010 Group Title

hmmm I feel dumb

20. kphilips2010 Group Title

why did your teacher say you were wrong?

21. burhan101 Group Title

i dont know she said there was something wrong with the method :S

22. kphilips2010 Group Title

does she know what she is talking about? LOL

23. kphilips2010 Group Title

sorry but i dont have another solution

24. burhan101 Group Title

is this what you're saying |dw:1350442853605:dw|

25. burhan101 Group Title

so do i keep the square root sign ?

26. joemath314159 Group Title

If you want to be rigorous about it, you need to state that for limits, you are looking at values of t close to -1, but NOT EQUAL to -1. if t is not equal to -1, then:$\frac{1-t^2}{1+t}=\frac{(1-t)(1+t)}{(1+t)}=1-t$We can only divide those monomials out if t DOESNT equal -1, which is ok in limits, we dont want t to equal -1. Im making an emphasis on the fact that if t was equal to -1, then that division doesnt make any sense.

27. burhan101 Group Title

ohh i see what you're saying

28. burhan101 Group Title

does the squareroot say there tho ?

29. joemath314159 Group Title

yes.

30. kphilips2010 Group Title

yes the sq rt stay

31. kphilips2010 Group Title

yay i was right.

32. burhan101 Group Title

thanks :D