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

OCR (not MEI) C1 - Wednesday 13th May 2015 Watch

    Offline

    1
    ReputationRep:
    (Original post by Brian luiz)
    Yes its stretch of scale factor 1/3 parallel to x axis
    I'm probably being stupid but it was 1/x to 1/3x iirc therefore a stretch of (1/3) aka timing by 1/3 would give 1/3x?
    Offline

    1
    ReputationRep:
    (Original post by AlfieH)
    A was 13 because..

    1) Differentiate the equation which was y=2x^3-ax^2+8x+2 which gives 6x^2-2ax+8
    2) Equate this to 0 for stationary point
    3) Plug in x=4 which gives 6(16)-8a+8=0
    4) Sort this out and rearrange etc to get 104=8a therefore 104/8=a which is 13/
    I made the god-awful mistake of somehow getting 8x^2-2ax+8, and carried on through all the parts... How many marks do you reckon I'll drop?
    Offline

    0
    ReputationRep:
    Everyones saying 40 but I got 20 root 5??
    Offline

    3
    ReputationRep:
    (Original post by waseemsharif54)
    Everyones saying 40 but I got 20 root 5??
    100% 40sq units
    Offline

    2
    ReputationRep:
    Posted from TSR Mobile

    Deffo 40. 10*8*0.5
    Offline

    1
    ReputationRep:
    (Original post by Rodgersd09)
    I made the god-awful mistake of somehow getting 8x^2-2ax+8, and carried on through all the parts... How many marks do you reckon I'll drop?
    Don't worry, I subtracted the 8 instead of plusing it and got a=11 and I couldn't find the other stationary point because of this mistake
    Offline

    1
    ReputationRep:
    (Original post by Parallex)
    the third root of -8 to the power of 4 is equal to the third root of 8 to the power of 4, so the answers would be the same
    Oh yes ofcourse. Silly my, i first put -1/48 as the answer because i used the substitution as x = 8 but then realised it was -8. Damn i forgot to change it lol
    Offline

    1
    ReputationRep:
    (Original post by User10102929)
    Attachment 397237Not 100% sure this is right, but this is how I got 'stretch by 1/3 in y-axis'
    This is exactly what I thought
    Offline

    2
    ReputationRep:
    (Original post by jt663)
    I'm probably being stupid but it was 1/x to 1/3x iirc therefore a stretch of (1/3) aka timing by 1/3 would give 1/3x?
    Ah im crap at transformations, you're probably right
    Offline

    0
    ReputationRep:
    (Original post by gabby07)
    100% 40sq units


    I must have worked out a length wrong then. Was point Q where the circle meets y axis (0,-2)?
    Offline

    2
    ReputationRep:
    Posted from TSR Mobile

    Yeah and R was 0,8
    Offline

    2
    ReputationRep:
    (Original post by gabby07)
    100% 40sq units
    i wrote 40 then crossed it out,
    will i get any method marks for working out the Q and R coordinates and writing area=.5x basex height ?
    (q out of 4)
    Offline

    2
    ReputationRep:
    (Original post by waseemsharif54)
    Everyones saying 40 but I got 20 root 5??
    Name:  400.png
Views: 311
Size:  3.8 KB
    Offline

    1
    ReputationRep:
    Was the radius of the circle 5? at the end
    Offline

    2
    ReputationRep:
    Posted from TSR Mobile

    Yup
    Offline

    3
    ReputationRep:
    (Original post by ChoccyPhilly)
    65/72 was unusually high for a core 1 exam. They're normally 61/62 and s1 and core 2 A marks are normally 56-59
    Yeah, in comparison, 2014 was more straightforward than this one as lot of of people tripped up. It's normally low 60s, high 50s.
    Offline

    0
    ReputationRep:
    (Original post by Parallex)
    Name:  400.png
Views: 311
Size:  3.8 KB


    thanks for that! I thought there was a right angle at point P which is why I didn't split into two triangles.
    Offline

    3
    ReputationRep:
    I got 40 square units
    -1/48
    stretch of 1/3 parallel to the y axis (can someone clarify on this please? not sure if right)
    k<-25/8
    Offline

    2
    ReputationRep:
    looks like a stretch parallel to x scale factor 1/3 to me tbh

    Attached Images
     
    Offline

    2
    ReputationRep:
    Posted from TSR Mobile

    You still get the same answer cuz distance from y axis to P stays the same for both
 
 
 
Poll
How are you feeling about your A-level results?

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.