Need help with Calculus problem

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Bound_Vortex

Member
Feb 6, 2000
91
0
66
Just a piece of advice, when given values for variables (i.e. x=2), leave the x in the original equation until all calculations and simplifications are done. She's learning the definition of a derivative, and it's better in the long run to see how variables are affected.

Knowing and understanding the derivation of a derivative will make understanding the many short-cuts she will learn in the next couple of weeks that much easier.

(also, Chrono has you going in the right direction)
 

Mo0o

Lifer
Jul 31, 2001
24,227
3
76
Originally posted by: Ender
Lol my AP class did that a week ago. It was easy stuff compared to what we're doing now.

What are you guys doing now? From waht I remember of AP calc the only annoying crap was the limits.
 

TuxDave

Lifer
Oct 8, 2002
10,571
3
71
Originally posted by: Mo0o
Originally posted by: Ender
Lol my AP class did that a week ago. It was easy stuff compared to what we're doing now.

What are you guys doing now? From waht I remember of AP calc the only annoying crap was the limits.

What about the good ol Convergence/Divergence of infinte series?
 

Ender

Golden Member
Jul 24, 2001
1,694
0
0
Originally posted by: Mo0o
Originally posted by: Ender
Lol my AP class did that a week ago. It was easy stuff compared to what we're doing now.

What are you guys doing now? From waht I remember of AP calc the only annoying crap was the limits.

We're learning trigonometric deivative formulae atm in addition to derivative formulae. Some of it's easy but the harder questions are really hard. I found limits simple to understand really. Just factor and substitute, nothing to it. Well, at least for now.
 

mobobuff

Lifer
Apr 5, 2004
11,099
1
81
To answer some questions (this is the girlfriend typing by the way):

Yes, I know this is the same as doing derivatives. That is the next chapter which I will be on as soon as I can do this assignment.

Yes, I know this wasn't really a "calculus" problem, but it's the algebra part of the calculus that I was having problems with.

And yes, the answer is -1, I just couldn't seem to get there. Thanks for the help (rgwalt) although I'm still a little confused on how it went from: ((1-(h+1))/(h+1))/h to (-h/(h+1))/h)... I see how the 1's cancel but I don't get the -h leftover. I'm sorry if this sounds stupid but it's late and my brain doesn't seem to function any longer.
 

Howard

Lifer
Oct 14, 1999
47,982
11
81
Originally posted by: Ender
Originally posted by: Mo0o
Originally posted by: Ender
Lol my AP class did that a week ago. It was easy stuff compared to what we're doing now.

What are you guys doing now? From waht I remember of AP calc the only annoying crap was the limits.

We're learning trigonometric deivative formulae atm in addition to derivative formulae. Some of it's easy but the harder questions are really hard. I found limits simple to understand really. Just factor and substitute, nothing to it. Well, at least for now.
Where do you go?
 

TuxDave

Lifer
Oct 8, 2002
10,571
3
71
Originally posted by: mobobuff
To answer some questions (this is the girlfriend typing by the way):

Yes, I know this is the same as doing derivatives. That is the next chapter which I will be on as soon as I can do this assignment.

Yes, I know this wasn't really a "calculus" problem, but it's the algebra part of the calculus that I was having problems with.

And yes, the answer is -1, I just couldn't seem to get there. Thanks for the help (rgwalt) although I'm still a little confused on how it went from: ((1-(h+1))/(h+1))/h to (-h/(h+1))/h)... I see how the 1's cancel but I don't get the -h leftover. I'm sorry if this sounds stupid but it's late and my brain doesn't seem to function any longer.

1-(h+1)=-h

heh.....
 

mobobuff

Lifer
Apr 5, 2004
11,099
1
81
AHHH!!!!! I see it now (and TuxDave that didn't really help, I couldn't picture the cancellation, I knew it was -h, I just couldn't see how it worked). Thanks for the help.
 

TuxDave

Lifer
Oct 8, 2002
10,571
3
71
Originally posted by: mobobuff
AHHH!!!!! I see it now (and TuxDave that didn't really help, I couldn't picture the cancellation, I knew it was -h, I just couldn't see how it worked). Thanks for the help.

Pardon me. I assumed when you said that you didn't get the -h leftover, that meant you didn't know how to get the -h. Nonetheless.... keep up the good work. Math = good for you.
 

mobobuff

Lifer
Apr 5, 2004
11,099
1
81
Thanks everyone. She was really frustrated with that and she's had a pretty bad day. She's writing furiously on her paper now so it seems you've shown her the light (or just plain gave her the answer after she didn't get it, either way, she's much happier). When she started making a reply to the thread I thought she was gonna start complaining and then you'd all flame her :) No but she's good now, the rest of her assignment was like that so she couldn't continue until she understood it. She's kicking herself for forgetting "basic algebra" ? :confused: This all looks like gibberish to me. I'll stick with computers :)

Thanks again.
 

AyashiKaibutsu

Diamond Member
Jan 24, 2004
9,306
4
81
Did you need to use the diffenition of derivitives? Or could you have just done f'(a/b) = (a'b-b'a)/b²