Eyes on Final Fantasy Forums > Reference > Study Hall > Help with some limits

[Hsu]

We used L'Hospital's rule last year, but technically since for this assignment "we" don't know derivatives I'm guessing that's not how much of the class will go about it. But I'll try those out whenever I've gotten up from my nap.

[rubah]

I realized just now that I typed that square root one into my calculator wrong, so I was looking at the wrong graph. It's actually asymptotic as x->3, so the limit doesn't exist. My bad!

[Doomie]

I know I should know this because I've done it all already, but logs were never my strong point. But I think I can vaguely remember a log rule that states that ln(x)^y = yln(x). I'm pretty sure you could use that here. You're also gonna need to clean things up a bit. I'm positive there's some sort of factoring or grouping you could do somewhere, but am way to tired to do it. Besides, I have my own homework to do. >=]

[NeoTifa]

Originally Posted by Del Murder ^

Have you ever heard of L Hopital's rule? Basically if you have a limit of a ratio you can take the derivative of the top and bottom pieces separately and it it will still result in the same limit.

For your first one you have:

derivative of top: 1/2*(x-2)^(-1/2) + 1/2*(6-x)^(-1/2)
derivative of bottom: 1

limit x->3 = 1/2*(3-2)^(-1/2) + 1/2*(6-3)^(-1/2)
= 1/2*(1) + 1/2*(1/sqrt(3))
= 1/2 + 1/(2*sqrt(3))

I'm not going to do the second one because it's your homework, and math is a bitch to type out.

*sob* can you help me w/ derivatives? i totally suck! i have like a 35% in calc ;_;

[qwertyxsora]

Originally Posted by NeoTifa ^

Originally Posted by Del Murder ^

Have you ever heard of L Hopital's rule? Basically if you have a limit of a ratio you can take the derivative of the top and bottom pieces separately and it it will still result in the same limit.

For your first one you have:

derivative of top: 1/2*(x-2)^(-1/2) + 1/2*(6-x)^(-1/2)
derivative of bottom: 1

limit x->3 = 1/2*(3-2)^(-1/2) + 1/2*(6-3)^(-1/2)
= 1/2*(1) + 1/2*(1/sqrt(3))
= 1/2 + 1/(2*sqrt(3))

I'm not going to do the second one because it's your homework, and math is a bitch to type out.

*sob* can you help me w/ derivatives? i totally suck! i have like a 35% in calc ;_;

Sure, just start a new thread and people will awnser your questions.