Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    10
    ReputationRep:
    Can anyone help me out?

    I know how to find the first but I am not sure how to continue:

    The question is to find th 2nd derivative as a function of x if siny+cosy=x
    Offline

    20
    ReputationRep:
    dy/dx = 1/{cosy-siny} now differentiate again wrt x
    • Thread Starter
    Offline

    10
    ReputationRep:
    Thanks, but I am really looking for a full answer and not just instructions. ^
    Online

    22
    ReputationRep:
    (Original post by FloralEssence)
    Thanks, but I am really looking for a full answer and not just instructions. ^
    But people here on TSR want to help you learn not just do the work for you, that means nudging you in the right direction. I'd suggest you take the hints and try and work through it.
    Online

    17
    ReputationRep:
    Not saying this is definitely easier, but if you're going to end up wanting an answer in terms of x, I'd be pretty tempted to start by rewriting \cos y + \sin y as R \sin(y + \alpha) for suitable choices of R, \alpha.
    • Thread Starter
    Offline

    10
    ReputationRep:
    (Original post by Zacken)
    But people here on TSR want to help you learn not just do the work for you, that means nudging you in the right direction. I'd suggest you take the hints and try and work through it.
    Apologies, my intentions were not to come across as unappreciative, but the truth is that I have pretty much exhausted my thought and am consistently getting very similar but different answers.

    Sometimes, it is easier to see how other people work things out and then adjust your method.

    Thank-you either way.
    • Study Helper
    Offline

    16
    ReputationRep:
    (Original post by FloralEssence)
    Apologies, my intentions were not to come across as unappreciative, but the truth is that I have pretty much exhausted my thought and am consistently getting very similar but different answers.

    Sometimes, it is easier to see how other people work things out and then adjust your method.

    Thank-you either way.
    If you post some working, people here can check it out for you and advise where you might be going wrong


    Notwithstanding that, DFranklin's suggestion is probably a good way to get started...
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    What newspaper do you read/prefer?
    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

    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
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • 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

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