Hi all,
Hope you are well.
Well I am having a little problem with Hyperbolic Functions....
How exactly would you work the following equation out....?
f 1/3x+5 dx
Just to let you know I know that f means function and other terms in the equation, however I am unsure how you would 'evaluate the above equation.
Would you need to separate the equation into something like....
1) sinh x =
2) cosh x =
3) tanh x =
sech x =???
If so how would I do this.
I imagine the derivatives of these equations below are...
d/dx (cosh x) = sinh x
d/dx (sinh x) = coshx
Correct =/?
However even if they are I do know how to use these analogue trig functions within the hyperbolic function above =/, I am stuck....
Hope you can help + appreciate your time.
Hyperbolic Functions  Math Course, SelfStudy

makaveli33
 Follow
 3 followers
 2 badges
 Visit makaveli33's homepage!
 Thread Starter
Offline2ReputationRep: Follow
 1
 15032012 05:14
Last edited by makaveli33; 15032012 at 06:00. 
makaveli33
 Follow
 3 followers
 2 badges
 Visit makaveli33's homepage!
 Thread Starter
Offline2ReputationRep: Follow
 2
 25032012 20:54
Thanks 
Coursework.info, I am trying my best to understand Math, it seems I need to keep trying as there is noone available.

 Follow
 3
 26032012 15:08
I don't understand what you are trying to do? I assume f means to integrate the function because of the dx at the end? Please clarify what you are doing and I can try to help.
If you are integrating then surely you can just use by recognition with log base eLast edited by George1337; 26032012 at 15:17.Post rating:1 
 Follow
 4
 26032012 15:13
Are you integrating? Is it (1/3x)+5 or 1/(3x+5). In either case, you don't need the hyperbolics.

makaveli33
 Follow
 3 followers
 2 badges
 Visit makaveli33's homepage!
 Thread Starter
Offline2ReputationRep: Follow
 5
 26032012 17:50
(Original post by George1337)
I don't understand what you are trying to do? I assume f means to integrate the function because of the dx at the end? Please clarify what you are doing and I can try to help.
If you are integrating then surely you can just use by recognition with log base e(Original post by tory88)
Are you integrating? Is it (1/3x)+5 or 1/(3x+5). In either case, you don't need the hyperbolics.
It is 1/(3x+5).
Assuming there is no need for hyperbolics, how is meant to be solved, oh and it does have a 'dx' during the end.
Apologies if the equation was confusing.
I could solve it through a calculator and attempt to work out how it was done.
However, your step by step guidance to be precise would be appreciated as there are many broadened knowledge in Math on this forum.
Thank you and all the best for all,
makaveli33
Postscript: What is strange is that if it does not need 'hyperbolics' why is it on an Alison (alison.com) course (Advanced Math I) this way, the assumption is because it is a contribution and it may be wrong.
Hope you can advise.
Kind regards.
Postscript II: To use a rough estimate of calculation, would it be....
0.333333*x+5
By the way  '0.333' is recurring, thanks.Last edited by makaveli33; 26032012 at 18:00. 
 Follow
 6
 26032012 18:14
(Original post by makaveli33)
Hi,
It is 1/(3x+5).
Assuming there is no need for hyperbolics, how is meant to be solved, oh and it does have a 'dx' during the end.

makaveli33
 Follow
 3 followers
 2 badges
 Visit makaveli33's homepage!
 Thread Starter
Offline2ReputationRep: Follow
 7
 26032012 18:24
(Original post by tory88)
But are you integrating it? If so it is a simple case of f'(x)/f(x) and if you're doing hyperbolics I imagine you are capable of integrating that? 
 Follow
 8
 26032012 18:30
(Original post by makaveli33)
Hi,
It is 1/(3x+5).
Assuming there is no need for hyperbolics, how is meant to be solved, oh and it does have a 'dx' during the end.
Apologies if the equation was confusing.
I could solve it through a calculator and attempt to work out how it was done.
However, your step by step guidance to be precise would be appreciated as there are many broadened knowledge in Math on this forum.
Thank you and all the best for all,
makaveli33
Postscript: What is strange is that if it does not need 'hyperbolics' why is it on an Alison (alison.com) course (Advanced Math I) this way, the assumption is because it is a contribution and it may be wrong.
Hope you can advise.
Kind regards.
Postscript II: To use a rough estimate of calculation, would it be....
0.333333*x+5
By the way  '0.333' is recurring, thanks.Post rating:1 
 Follow
 9
 26032012 18:31
(Original post by makaveli33)
Sorry, I did not mention it is an antiderivative, :/ 
makaveli33
 Follow
 3 followers
 2 badges
 Visit makaveli33's homepage!
 Thread Starter
Offline2ReputationRep: Follow
 10
 26032012 18:56
(Original post by tory88)
In which case, can you get 1/(3x+5) into the standard form f'(x)/f(x)? 
 Follow
 11
 26032012 19:00
(Original post by makaveli33)
x = 3 or 3???? 
makaveli33
 Follow
 3 followers
 2 badges
 Visit makaveli33's homepage!
 Thread Starter
Offline2ReputationRep: Follow
 12
 26032012 19:08
(Original post by tory88)
This is an integration (antiderivative if you prefer)  you can't solve for x like that. What, for instance, is the antiderivative of 1/x?
Antiderivative = ln(x)
I know why, because they are opposites.
Deep into the theory, the reasons are, because an antiderivative is the first step of the equation, a derivative is the second step of the equation or a solved equation as such, the antiderivative goes to the original equation based on the later one.
The problem I find with this is, having difficulty working out how to quickly and efficiently do larger sums/equations.
Thanks. 
 Follow
 13
 26032012 19:14
The general rule for this sort of thing is to change it into the form of derivative over function, then it is just ln(function). So with 1/x, x is the function and 1 is its derivative. With that, how can you get 1/(3x+5) into this form?
Post rating:1 
 Follow
 14
 26032012 19:25
Hello,
So you have: integrate [1/(3x+5)] dx
If you want to solve this quickly you can use a method called "Advanced guessing".
since you have something similar to 1/x, we know that 1/x dx = ln(x).
Let us say that y=ln(3x+5)
differentiating this we get I=1/(3x+5) * 3 =3/(3x+5), so I= 3/(3x+5)
However we need I to equal to 1/(3x+5), so, we must divide y by 3.
When y=(1/3)(ln(3x+5) differentiating this will give 1/(3x+5)
Hope that helps!
Let me know if this helps
Thanks!Last edited by sulexk; 26032012 at 19:27.Post rating:1 
makaveli33
 Follow
 3 followers
 2 badges
 Visit makaveli33's homepage!
 Thread Starter
Offline2ReputationRep: Follow
 15
 26032012 19:54
(Original post by sulexk)
Hello,
So you have: integrate [1/(3x+5)] dx
If you want to solve this quickly you can use a method called "Advanced guessing".
since you have something similar to 1/x, we know that 1/x dx = ln(x).
Let us say that y=ln(3x+5)
differentiating this we get I=1/(3x+5) * 3 =3/(3x+5), so I= 3/(3x+5)
However we need I to equal to 1/(3x+5), so, we must divide y by 3.
When y=(1/3)(ln(3x+5) differentiating this will give 1/(3x+5)
Hope that helps!
Let me know if this helps
Thanks!(Original post by tory88)
The general rule for this sort of thing is to change it into the form of derivative over function, then it is just ln(function). So with 1/x, x is the function and 1 is its derivative. With that, how can you get 1/(3x+5) into this form?
ln(3x+5)
Assuming this is the way.
Explained, essentially....
Because ln(x) is 1/x (opposite) then....
You times 1/x by 3 it makes 1/3x and the +5 is nonchanging as it is not a x value.
Thank you so much.
You guys are amazing.
I hope that what was said makes sense and was correct, however have a gut feeling there is understanding.
I will rep everyone on this thread for their contributions.
That advancedguessing is an amazing technique =)!!!!
Using smaller figures to make larger ones and advguessing is very useful, thank you ever so much! 
 Follow
 16
 27032012 00:01
(Original post by makaveli33)
OMG, Thank you, this makes....
ln(3x+5)
Assuming this is the way.
Explained, essentially....
Because ln(x) is 1/x (opposite) then....
You times 1/x by 3 it makes 1/3x and the +5 is nonchanging as it is not a x value.
Thank you so much.
You guys are amazing.
I hope that what was said makes sense and was correct, however have a gut feeling there is understanding.
I will rep everyone on this thread for their contributions.
That advancedguessing is an amazing technique =)!!!!
Using smaller figures to make larger ones and advguessing is very useful, thank you ever so much!
You have ln(3x+5), differentiating this, will give [1/(3x+5)] *3, the *3 comes from differentiating what is inside the brackets. I can explain this using the "CHAIN RULE":
Don't Worry, if you have never seen this before, I will try and explain it as simply as I can:
Let us use the above for our example:
say "y=ln(3x+5)", and I said to you "I want to differentiate this", you will say to me "you have a function (3x+5) within another function ln(). so we have a function within a function!
Suppose, I said to you let us say that u=3x+5.
then simply put y=ln(u)
now if I want to differentiate, I can only find dy/du, since the right hand side is in terms of u, but I want to find dy/dx, so what do I do?
Well now let us use some intriguing manipulation:
(dy/du) * (du/dx) = dy/dx
now how do we find dy/du and du/dx
Well, dy/du = derivative of y=ln(u) which is 1/u
so dy/du=1/u
we know u=3x+5, so du/dx = 3
then substituting these into the above: (dy/du) * (du/dx) = dy/dx
(1/u)*(3)=3/u as u=3x+5
then dy/dx = 3/(3x+5)
and there you have it a manipulation of the chain rule to find the derivative of y=ln(3x+5)
If you want some practice with this, feel free to try some examples below:
Find the derivative of each of the following:
1) y= 1/(4x+5)
2) y= sin(3x+5)
3) y=1/(x^2 + 1)
4) y=(x+1)^2
5)y=cos(x^2 + 1)
6) y=2/sin(x)
When you finished feel free to let me know, and I'll answer them and put up the solutions!
Practice is the way forward! If you want me to provide you with some applied problems, let me know! (I can give you some rate of change problems!).
hope that helps!!Last edited by sulexk; 28032012 at 12:39. 
makaveli33
 Follow
 3 followers
 2 badges
 Visit makaveli33's homepage!
 Thread Starter
Offline2ReputationRep: Follow
 17
 28032012 12:11
(Original post by sulexk)
Yes.
You have ln(3x+5), differentiating this, will give [1/(3x+5)] *3, the *3 comes from differentiating what is inside the brackets. I can explain this using the "CHAIN RULE":
Don't Worry, if you have never seen this before, I will try and explain it as simply as I can:
Let us use the above for our example:
say "y=ln(3x+5)", and I said to you "I want to differentiate this", you will say to me "you have a function (3x+5) within another function ln(). so we have a function within a function!
Suppose, I said to you let us say that u=3x+5.
then simply put y=ln(u)
now if I want to differentiate, I can only find dy/du, since the right hand side is in terms of u, but I want to find dy/dx, so what do I do?
Well now let us use some intriguing manipulation:
(dy/du) * (du/dx) = dy/dx
now how do we find dy/du and du/dx
Well, dy/du = derivative of y=ln(u) which is 1/u
so dy/du=1/u
we know u=3x+5, so du/dx = 3
then substituting these into the above: (dy/du) * (du/dx) = dy/dx
(1/u)*(3)=3/u as u=3x+5
then dy/dx = 3/(3x+5)
and there you have it a manipulation of the chain rule to find the derivative of y=3x+5
If you want some practice with this, feel free to try some examples below:
Find the derivative of each of the following:
1) y= 1/(4x+5)
2) y= sin(3x+5)
3) y=1/(x^2 + 1)
4) y=(x+1)^2
5)y=cos(x^2 + 1)
6) y=2/sin(x)
When you finished feel free to let me know, and I'll answer them and put up the solutions!
Practice is the way forward! If you want me to provide you with some applied problems, let me know! (I can give you some rate of change problems!).
hope that helps!!
ln(2x+sin)
Using this method....
((dy/du) * (du/dx) = dy/dx))
then....
1/u * (2) = 2/u and u= 2x + sine or sin
Hope this is correct.
By the way, your math methods are amazing, sulexk, you make Math and calculus appear so easy by your problem solving, you deserve a tap on the back! =)Last edited by makaveli33; 28032012 at 12:12. 
 Follow
 18
 28032012 12:53
(Original post by makaveli33)
is 6)....
ln(2x+sin)
Using this method....
((dy/du) * (du/dx) = dy/dx))
then....
1/u * (2) = 2/u and u= 2x + sine or sin
Hope this is correct.
By the way, your math methods are amazing, sulexk, you make Math and calculus appear so easy by your problem solving, you deserve a tap on the back! =)
the last one is a bit tricky, it actually doesn't require the use of ln(x):
So we have, y=2/sin(x)
if we let u=sin(x), then y=2/u=2u^1
so dy/du=2u^2
du/dx = cos(x)
put the two together: (dy/du)*(du/dx) = dy/dx = (2u^2)*(cos(x))
(2u^2)*(cos(x))=(2(sin(x)^2))*(cos(x))
(2(sin(x)^2)*(cos(x)) = [2/(sin(x)^2)]*(cos(x))=2cos(x)/[sin(x)^2]
Hope that helps!
If you need any more problems for the chain rule, or any other differentiation type problems, feel free to let me know! 
makaveli33
 Follow
 3 followers
 2 badges
 Visit makaveli33's homepage!
 Thread Starter
Offline2ReputationRep: Follow
 19
 30032012 02:01
(Original post by sulexk)
Hi,
the last one is a bit tricky, it actually doesn't require the use of ln(x):
So we have, y=2/sin(x)
if we let u=sin(x), then y=2/u=2u^1
so dy/du=2u^2
du/dx = cos(x)
put the two together: (dy/du)*(du/dx) = dy/dx = (2u^2)*(cos(x))
(2u^2)*(cos(x))=(2(sin(x)^2))*(cos(x))
(2(sin(x)^2)*(cos(x)) = [2/(sin(x)^2)]*(cos(x))=2cos(x)/[sin(x)^2]
Hope that helps!
If you need any more problems for the chain rule, or any other differentiation type problems, feel free to let me know!
There are a lot of rules to remember :/
Will do some reading on the chain rule.
Thanks =). 
makaveli33
 Follow
 3 followers
 2 badges
 Visit makaveli33's homepage!
 Thread Starter
Offline2ReputationRep: Follow
 20
 30032012 16:57
(Original post by sulexk)
Hi,
the last one is a bit tricky, it actually doesn't require the use of ln(x):
So we have, y=2/sin(x)
if we let u=sin(x), then y=2/u=2u^1
so dy/du=2u^2
du/dx = cos(x)
put the two together: (dy/du)*(du/dx) = dy/dx = (2u^2)*(cos(x))
(2u^2)*(cos(x))=(2(sin(x)^2))*(cos(x))
(2(sin(x)^2)*(cos(x)) = [2/(sin(x)^2)]*(cos(x))=2cos(x)/[sin(x)^2]
Hope that helps!
If you need any more problems for the chain rule, or any other differentiation type problems, feel free to let me know!
I have done some reading on the chain rule, there are many variations for the type of integer or type, using this...
http://www.sosmath.com/calculus/diff/der04/der04.html
I think it is a matter of practice, I will try to solve some of your questions as soon as possible, using the support given and the website, it is all a matter of practice =).
Thanks.
Write a reply…
Reply
Submit reply
Register
Thanks for posting! You just need to create an account in order to submit the post Already a member? Sign in
Oops, something wasn't right
please check the following:
Sign in
Not got an account? Sign up now
Updated: April 2, 2012
Share this discussion:
Tweet
Related discussions:
 The "Is this university/course good enough for banking ...
 Actuarial Science chat
 Cambridge Natural Sciences (NatSci) Students and ...
 Cambridge Natural Sciences (NatSci) Students and ...
 Advanced Higher Mathematics 2015/16  Discussion and Help ...
 Oxford PPE (Philosophy, Politics and Economics) Students ...
 Oxford PPE (Philosophy, Politics and Economics) Students ...
 Official Cambridge Applicants 2015 Entry
 Physics 2014 Entry Hopefuls!
 2015 Physics Applicants
TSR Support Team
We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.