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

    0
    ReputationRep:
    ABC is a right angled triangle as shown in the diagram. A rectangle AXYZ is drawn around the triangle, with the angle XAB = theta

    By expressing the perimieter of the rectangle in the form R cos (theta - alpha), find:

    a) the maximum perimieter of the rectangle as theta varies

    b) the corresponding value of theta, giving your answer to the nearest 0.1 of a degree.



    The picture I've attached is just a quick one I've drawn of the image I have on the pice of paper. The sides of the triangle I've been given are 2 and 1 as I've tried to show on my drawing.

    How do I go about starting this? I'm literally blank.
    Offline

    1
    ReputationRep:
    What's |AX|? |XB|?

    If you're stuck on something like this, just use trig/angle rules/pythagoras to work out as many lengths/angles as you can, and see if it gets you anywhere.
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by Daniel Freedman)
    What's |AX|? |XB|?

    If you're stuck on something like this, just use trig/angle rules/pythagoras to work out as many lengths/angles as you can, and see if it gets you anywhere.

    We're not given AX or XB, I've put everything we have on that diagram.

    I'll have a quick look through my notes and revision book and see if I can find anything that looks like this tomorrow. I'll see if anyone else has done it as well.
    Offline

    1
    ReputationRep:
    (Original post by TheBlueNowhere)
    We're not given AX or XB, I've put everything we have on that diagram.

    I'll have a quick look through my notes and revision book and see if I can find anything that looks like this tomorrow. I'll see if anyone else has done it as well.
    I meant "from the information given, what is |AX|"? There's enough information to find it in terms of theta, which is what you want.

    EDIT: Changed '|AB|' to '|AX|'
    Offline

    0
    ReputationRep:
    theta=0 perimiter=6?
 
 
 
  • 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
    Has a teacher ever helped you cheat?
    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

    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.