Join TSR now and get all your revision questions answeredSign up now

Edexcel C1 arithmetic series question 5 January 2014 IAL paper Watch

    • Thread Starter
    Offline

    3
    ReputationRep:
    Hi,

    How would you do parts (b) and (c) for this question?
    Please could you also show the steps to how you got the answer as well?

    Thank you!
    Attached Images
     
    • Very Important Poster
    Offline

    3
    ReputationRep:
    (Original post by Shanahey)
    Hi,

    How would you do parts (b) and (c) for this question?
    Please could you also show the steps to how you got the answer as well?

    Thank you!
    (b) and (c) rely on (a). What did you get for those values?

    It helps to think about what went on from u2 to u3 to u4, and what u5 will be.
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by SeanFM)
    (b) and (c) rely on (a). What did you get for those values?

    It helps to think about what went on from u2 to u3 to u4, and what u5 will be.
    Hi,
    I got U2 as 2/3, U3 as -4 and u4 as 3
    • Very Important Poster
    Offline

    3
    ReputationRep:
    (Original post by Shanahey)
    Hi,
    I got U2 as 2/3, U3 as -4 and u4 as 3
    Brilliant

    Without further calculation, can you see what u5 would be? (You can calculate it if you want but hopefully you spot something else).
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by SeanFM)
    Brilliant

    Without further calculation, can you see what u5 would be? (You can calculate it if you want but hopefully you spot something else).
    U5 would be 2/3?
    • Very Important Poster
    Offline

    3
    ReputationRep:
    (Original post by Shanahey)
    U5 would be 2/3?
    Bingo. Can you see the pattern?
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by SeanFM)
    Bingo. Can you see the pattern?
    Yeah I can see the pattern, but how would you find U61 straight away?
    • Very Important Poster
    Offline

    3
    ReputationRep:
    (Original post by Shanahey)
    Yeah I can see the pattern, but how would you find U61 straight away?
    Well, the terms seem to appear in sets (which you'll have worked out as sets of 3 - a,b,c).

    So U1 = a, U2 = b, U3 = c (for the first 3 numbers), U4 = a .... (for the numbers 4-6)... what will U61 be?
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by SeanFM)
    Well, the terms seem to appear in sets (which you'll have worked out as sets of 3 - a,b,c).

    So U1 = a, U2 = b, U3 = c (for the first 3 numbers), U4 = a .... (for the numbers 4-6)... what will U61 be?
    Thank you! How would you do part (c)?
    • Very Important Poster
    Offline

    3
    ReputationRep:
    (Original post by Shanahey)
    Thank you! How would you do part (c)?
    The clue is that it's the sum of the *99* terms. Now think about your set of .... and you should be able to find the sum.
 
 
 
Poll
How are you feeling about your A-level results?
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

Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.