Turn on thread page Beta
    • Thread Starter
    Offline

    15
    ReputationRep:
    If i have got 36v.dv/36+v^2 =-g.dx
    and i have to integrate what would i get on the left hand side? Ik i will get -gx+c on the right hand and i will get ln on the left but what goes in front of the ln?
    • Community Assistant
    Offline

    20
    ReputationRep:
    Community Assistant
    (Original post by English-help)
    If i have got 36v.dv/36+v^2 =-g.dx
    and i have to integrate what would i get on the left hand side? Ik i will get -gx+c on the right hand and i will get ln on the left but what goes in front of the ln?
    This is so ambiguous...

    Do you mean \displaystyle \frac{36v}{36+v^2} .dv = -g .dx ??

    In which case, what is the derivative of 36+v^2?? How can you manipulate the numerator to make it equal to that derivative?
    • Thread Starter
    Offline

    15
    ReputationRep:
    (Original post by RDKGames)
    This is so ambiguous...

    Do you mean \displaystyle \frac{36v}{36+v^2} .dv = -g .dx ??

    In which case, what is the derivative of 36+v^2?? How can you manipulate the numerator to make it equal to that derivative?
    Yes i mean that!
    The derivative of 36+v^2 is 2v and you have to times by 2 if you take the 36 outside
    • Community Assistant
    Offline

    20
    ReputationRep:
    Community Assistant
    (Original post by English-help)
    Yes i mean that!
    The derivative of 36+v^2 is 2v and you have to times by 2 if you take the 36 outside
    But then you'd have 72v if you do that.

    Just factor out 18.
    Offline

    21
    ReputationRep:
    Turn the inside of the integration on the left into f'(x)/f(x), should then know what integrating this makes.
    • Thread Starter
    Offline

    15
    ReputationRep:
    (Original post by RDKGames)
    But then you'd have 72v if you do that.

    Just factor out 18.
    Okay ill factor out 18! Yeah ive done it thanks
    Offline

    20
    ReputationRep:
    it is best to put modulus lines when you get ln?

    ln |?|

    although in this case 36 + v2 will always be positive.|
 
 
 

University open days

  • University of Warwick
    Undergraduate Open Days Undergraduate
    Sat, 20 Oct '18
  • University of Sheffield
    Undergraduate Open Days Undergraduate
    Sat, 20 Oct '18
  • Edge Hill University
    Faculty of Health and Social Care Undergraduate
    Sat, 20 Oct '18
Poll
Who is most responsible for your success at university
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Equations

Best calculators for A level Maths

Tips on which model to get

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.