Hey there! Sign in to join this conversationNew here? Join for free

How would you show that 1/ (1 + cos x) = tan (x/2) +c watch

    • Thread Starter
    Offline

    18
    ReputationRep:
    I am so so so confused
    • Thread Starter
    Offline

    18
    ReputationRep:
    (Original post by TeeEm)
    cos2x = 2cos2x - 1
    cosx = 2cos2(x/2) - 1
    Then what
    • Community Assistant
    • Study Helper
    Offline

    20
    ReputationRep:
    Community Assistant
    Study Helper
    (Original post by APersonYo)
    Then what
    Susbtitute for \cos x using the identity TeeEm gave you. Please post all your working if you get stuck.
    • Thread Starter
    Offline

    18
    ReputationRep:
    (Original post by notnek)
    Susbtitute for \cos x using the identity TeeEm gave you. Please post all your working if you get stuck.
    I usually post my working. But I am so stuck on this question I have no working
    • Community Assistant
    • Study Helper
    Offline

    20
    ReputationRep:
    Community Assistant
    Study Helper
    (Original post by APersonYo)
    I usually post my working. But I am so stuck on this question I have no working
    TeeEm showed you this:

    cosx = 2cos2(x/2) - 1

    So change the cos(x) in 1/(1+cos(x)) using the above identity. Try this and please post what you get if you get stuck.
 
 
 
Poll
Do you agree with the PM's proposal to cut tuition fees for some courses?
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

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.