Turn on thread page Beta
    • Thread Starter
    Offline

    2
    ReputationRep:
    Name:  image.jpg
Views: 87
Size:  489.5 KBHi, my class recently started doing C3 and for some reason my teacher chose to begin with trig. He gave us some questions but I can't do any of them and I'm now in desperate need of help.
    • Community Assistant
    Offline

    20
    ReputationRep:
    Community Assistant
    (Original post by Leandra_chk)
    Hi, my class recently started doing C3 and for some reason my teacher chose to begin with trig. He gave us some questions but I can't do any of them and I'm now in desperate need of help.
    For part a, use the first identity and divide it through by sin2

    For part b, use your newly derived identity and leave cosec2 on one side, then square both sides to get an expression for cosec4 in terms of cot. Do the same to get cot4 in terms of cosec. Then just subtract cot4 from cosec4. Mess around with that expression and you should get there... or just difference of 2 squares.

    For c, replace the left hand side with the alternative. Then you can express cosec2 in terms of cot2. Mess around with that and you should arrive to a quadratic which you can solve. I got values for cot to be 1/2 and -1. Since you know cot=1/tan, you can use this to solve for theta in the range between 90 and 180 degrees using general solutions or however else you solve them in Core 2.

    I suppose you noted these down but in case you haven't: cosec=1/sin , sec=1/cos and cot=1/tan=cos/sin
    Offline

    21
    ReputationRep:
    (Original post by Leandra_chk)
    Name:  image.jpg
Views: 87
Size:  489.5 KBHi, my class recently started doing C3 and for some reason my teacher chose to begin with trig. He gave us some questions but I can't do any of them and I'm now in desperate need of help.
    For b you should see it is the difference between two squares. Factorise it and use the result from a


    Posted from TSR Mobile
    • Community Assistant
    Offline

    20
    ReputationRep:
    Community Assistant
    (Original post by gdunne42)
    For b you should see it is the difference between two squares. Factorise it and use the result from a


    Posted from TSR Mobile
    God dammit, why didn't I think of that. I knew there was something faster I just couldn't put my finger on it. -_-
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: June 29, 2016
Poll
Favourite type of bread
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.