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

    14
    Quick question- why does the three not get cancelled out?

    Name:  image.jpg
Views: 95
Size:  338.2 KB
    Spoiler:
    Show
    Don't judge
    Offline

    10
    ReputationRep:
    (Original post by Questioness)
    Quick question- why does the three not get cancelled out?

    Name:  image.jpg
Views: 95
Size:  338.2 KB
    Spoiler:
    Show
    Don't judge
    Because you are mutliplying the theta by 3, not the entire trig function by 3.

    In general \sin 3x \neq 3\sin x . e.g. \sin 90 = 1 but \sin 270 = -1 .
    Offline

    17
    ReputationRep:
    (Original post by Questioness)
    Quick question- why does the three not get cancelled out?

    Name:  image.jpg
Views: 95
Size:  338.2 KB
    Spoiler:
    Show
    Don't judge
    To recast the question to you: Why do you think the 3 should cancel?
    Online

    13
    ReputationRep:
    Let y=3 \theta Now do the question and see...
    • Thread Starter
    Offline

    14
    (Original post by Farhan.Hanif93)
    To recast the question to you: Why do you think the 3 should cancel?
    Oh, I think I understand this now. So, if it were to divide by just costheta and not cos3theta then it wouldn't make tan3theta.
 
 
 
  • 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
    Brussels sprouts
    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.