Turn on thread page Beta
    • Thread Starter
    Offline

    3
    ReputationRep:
    solve the equation for 0<Ɵ<360 : tan^^2 Ɵ=2 and 3cos^^2 Ɵ 2cos Ɵ -1 = 0 I'm honestly baffled
    Offline

    20
    ReputationRep:
    Is there an equation which links sec^2Ɵ to tan^2Ɵ? As secƟ = 1/cosƟ.
    • Community Assistant
    • Study Helper
    Offline

    20
    ReputationRep:
    Community Assistant
    Study Helper
    (Original post by Sweetpotayto)
    solve the equation for 0<Ɵ<360 : tan^^2 Ɵ=2 and 3cos^^2 Ɵ 2cos Ɵ -1 = 0 I'm honestly baffled
    Are these two separate questions? And is this GCSE further maths? It's not normal GCSE maths.

    The second equation isn't clear, there looks to be a sign missing.
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by Notnek)
    Are these two separate questions? And is this GCSE further maths? It's not normal GCSE maths.

    The second equation isn't clear, there looks to be a sign missing.
    ohhh sugar, yeah it's further maths and there are 2 different equations... the last one is 3cos^^2 + 2cos Ɵ -1 = 0
    • Community Assistant
    • Study Helper
    Offline

    20
    ReputationRep:
    Community Assistant
    Study Helper
    (Original post by Sweetpotayto)
    ohhh sugar, yeah it's further maths and there are 2 different equations... the last one is 3cos^^2 + 2cos Ɵ -1 = 0
    Okay so for the first equation, do you have any ideas for how to solve it?

    It's best that you say this is further maths if you post it as a GCSE question otherwise people will be confused. Also, please post maths questions in the Maths forum - I've moved this one for you.
    • Thread Starter
    Offline

    3
    ReputationRep:
    I know tanƟ is either square root 2 or -2

    so 54.7 or -54.7 and then that's where I get baffled.

    But I know that it's going to be 180 + 54.7 = 234.7

    so I can do it for +2 but not -2 ... if that makes any sense
    • Community Assistant
    • Study Helper
    Offline

    20
    ReputationRep:
    Community Assistant
    Study Helper
    (Original post by Sweetpotayto)
    I know tanƟ is either square root 2 or -2

    so 54.7 or -54.7 and then that's where I get baffled.

    But I know that it's going to be 180 + 54.7 = 234.7

    so I can do it for +2 but not -2 ... if that makes any sense
    You'd have to tell me which method you use to find trig solutions e.g. CAST, the graph etc.

    But for tan, adding/subtracting 180 will always get you solutions so you can just do this i.e. add 180 to -54.7 for a solution in the range and then add 180 again...
    • Thread Starter
    Offline

    3
    ReputationRep:
    I just realised that for the - root 2 it's 125.3 so 180+ 125.3 is 305.3 .... so the solutions are 54.7, 125.3, 234.7 and 305.3?
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: March 1, 2018
Poll
Cats or dogs?
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.