rscott9399
New member
- Joined
- Jul 6, 2017
- Messages
- 6
Moderator Note: The posts in this thread have been split from:
https://www.freemathhelp.com/forum/threads/107655-Limit-Help-sqr-(9-y-2)-(-y-3-)-as-y-approaches-3
The very definition of a limit implies that the function DNE beyond the intended point of inspection.
When infact the Limit absolutely DOES EXIST! The function no longer exists in the real number domain beyond -3 but the limit does 100% exist
and the answer to it is sqrt(6) or 2.44
Do you know how to get that?
How far are you in calc? Do you know what a Derivative is yet?
The way to solve this is what is called L'Hospital's Rule
https://en.wikipedia.org/wiki/L'Hôpital's_rule
Essentially for rational functions like this what you want to do is take the derivative of the numerator and denominator. Leave the sqrt alone
This will leave you with Sqrt(-2*y/1)
Then you evaluate the function at -3
Sqrt ( -2*-3/1) = Sqrt (-6) or 2.44
Which is why in the above graph that the other person posted there is a vertical asymptotic line at 2.44
So to say the limit DNE is flat out wrong the answer is sqrt(6). And to say the function DNE beyond -3 is technically wrong as well as it DOES exist just not in the real domain.
If you need further clarification please let me know
https://www.freemathhelp.com/forum/threads/107655-Limit-Help-sqr-(9-y-2)-(-y-3-)-as-y-approaches-3
The very definition of a limit implies that the function DNE beyond the intended point of inspection.
When infact the Limit absolutely DOES EXIST! The function no longer exists in the real number domain beyond -3 but the limit does 100% exist
and the answer to it is sqrt(6) or 2.44
Do you know how to get that?
How far are you in calc? Do you know what a Derivative is yet?
The way to solve this is what is called L'Hospital's Rule
https://en.wikipedia.org/wiki/L'Hôpital's_rule
Essentially for rational functions like this what you want to do is take the derivative of the numerator and denominator. Leave the sqrt alone
This will leave you with Sqrt(-2*y/1)
Then you evaluate the function at -3
Sqrt ( -2*-3/1) = Sqrt (-6) or 2.44
Which is why in the above graph that the other person posted there is a vertical asymptotic line at 2.44
So to say the limit DNE is flat out wrong the answer is sqrt(6). And to say the function DNE beyond -3 is technically wrong as well as it DOES exist just not in the real domain.
If you need further clarification please let me know
Last edited by a moderator: