maths t paper 2 2009 johor - marking scheme

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  • 8/14/2019 Maths t Paper 2 2009 Johor - Marking Scheme

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    1

    JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATANJABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATANJABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATANJABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATANJABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATANJABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN

    JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATANJABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATANJABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATANJABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATANJABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATANJABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATANJABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATANJABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN PELAJARAN JOHOR JABATAN

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    MATHEMATICS T(MATEMATIK T)

    PAPER 2(KERTAS 2)

    PERCUBAAN

    STPM 2009

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    2

    Q Steps Marks Notes

    1

    ~a

    ~b

    ~~ba

    cos =))(( 352

    735222 +

    0120=

    Thus, angle between~a and

    ~b is 120

    0

    1

    1

    1

    1

    4

    Diagram with arrow in

    correct direction

    using cosine rule

    CA

    conclusion

    1 Alternative method:

    =

    y

    xa~

    ,

    =

    n

    mb~

    x2

    +y2

    = 25 and m2

    + n2

    = 9

    =

    ny

    mxba~~

    (x m)2 + (y m)2 = 49x

    2+ y

    2+m

    2+n

    2 2mx 2ny = 49

    mx + ny =2

    15

    cos||||.~~~~baba =

    n

    m

    y

    x. = 5 x 3cos

    xm + yn = 5x3cos

    2

    15 = 5x3cos

    cos =2

    1

    = 1200Hence, the angle between

    ~a and

    ~b is 120

    0

    1

    1

    1

    1

    4

    Either one correct

    Dot product

    CA

    conclusion

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    3

    2 3sinx + 4cos x = r sinx cos + rcos x sin rcos = 3 , rsin = 4

    r = 5 or 22 43 + seen

    tan =

    3

    4

    = 53.10Hence,

    3sinx + 4cos x 5 sin(x + 53.10)

    6 sin x + 8 cos x + 5 = 10 sin(x + 53.10

    ) + 5

    -5 10 sin(x + 53.10 ) + 5 15Max. value = 15

    Min. value = -5

    1

    1

    1

    1

    1

    1

    6

    both

    rcos = 3rsin = 4 seen,if not, -1

    for10 sin(x + 53.10 ) + 5

    For his logic

    inequality

    Both values correct

    3(a)

    (b)

    vQ

    vP

    Pv

    Q

    300

    1200

    QvP= 30

    2+ 60

    2 2(30)(60)cos 120

    0

    QvP= 30 7 or 79.37 km

    37379

    120

    30

    0

    .

    sinsin=

    = 19.110 / 19.10

    Direction ofQvPis S 49.10

    W

    Shortest distance = 20 sin 40.90

    = 13.09 km

    1

    1

    1

    1

    1

    1

    1

    7

    Diagram withcorrect arrows

    Cosine rule based on

    his diagram

    CA

    His sine rule

    CA

    Using his angleCA

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    4

    4. 2 sin2

    x = 1 cos 2x

    sin 3x = sin(2x + x)

    = sin 2x cos x + cos 2x sin x

    = 2 sin x cos2x + ( 1 2sin

    2x)sin x

    = 2 sin x(1 sin2

    x) + sin x 2 sin3

    x

    = 3 sin x 4 sin3x

    8 sin 5 x = (2sin2

    x)(4sin3

    x)

    = (1 cos 2x)(3 sin x sin 3x)

    = 3 sin x sin 3x 3cos 2x sin x + sin 3xcos 2x

    = 3 sin x sin 3x 3[ sin 3x sin x] + sin 5x

    + sin x

    = 5 sin x -2

    5sin 3x + sin 5x

    Hence, a = 5, b = -2

    5, c =

    2

    1

    1

    1

    1

    1

    1

    1

    1

    7

    CA

    Identity(either one)

    CA

    Using above ans.

    Either one of the factor

    formula used

    CA

    conclusion

    5(a)

    C

    D

    O

    BCO = BAO = 900(radius perpendicular to tangent)BO = BO (common line)

    OC = OA (radii of circle)

    BAO BCO (RHS)

    BC = AB

    1

    1

    1

    1

    Must provide at least 1

    correct reason, if not -1

    Must have above 3statements evenwithout RHS

    BAO BCO seen

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    5

    (b)

    (c)

    A

    C

    D

    E

    OB

    x0x

    0

    x0

    900-x0

    Let AOE be the diameter of the circle,

    CAE = 900 x0(tangent to radius)ECA = 900(angle in semicircle)CEA = 1800 (900- x0) - 900

    = x0

    CDA =CEA = x0(angle in same segment)BAC =ADC

    C

    D

    BAC = ADC = x0(from above)

    ACD = x0 (base angle of isosceles ) either oneBCA= x0(base angle of isosceles /alternate segment)ACD =BCADAC = 900 2x0 = ABC

    Hence, ACD ADC

    1

    1

    1

    1

    1

    1

    1

    1

    12

    Mark accordingly to his

    labelling

    Must provide at least 1

    correct reason, if not -1

    All the above 3

    statements correct

    Must provide at least 1

    correct reason, if not -1

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    6

    6a

    pdt

    dp

    2

    312 = = )( p324

    2

    1

    = dtpdp

    2

    1

    324

    ctp +=2

    1324

    3

    1)ln(

    c+= )()](ln[ 02

    10324

    3

    1

    243

    1ln=c

    243

    1

    2

    1324

    3

    1ln)ln( = tp

    tp 2

    3

    324

    24=

    ln

    t

    ep

    2

    3

    24

    324 =

    p = 8 8t

    e 23

    = 8(1-t

    e 23

    )

    p

    t0

    8

    1

    1

    1

    1

    1

    1

    1

    7

    Any correct separation

    Integrate

    Correct subst. for

    finding c

    Get rid of ln

    CA

    Shape of curve & 8seen.

    All correct

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    7

    6(b22vgkg

    dt

    dv=

    =gdt

    vk

    dv22

    1

    By writing

    kv

    B

    kv

    A

    kvkv +

    +

    =

    + 1111

    1

    ))((

    1 = A(1 + kv) + B(1 kv)

    A =2

    1, B =

    2

    1

    =++

    gdtdv

    kvkv )()( 12

    1

    12

    1

    cgtkv

    kv

    k+=

    +

    1

    1

    2

    1ln

    ( ) cgk += )(ln 0121

    kgtkv

    kv2

    1

    1=

    +ln

    kgte

    kv

    kv 2

    1

    1=

    +

    kgtekvkv 211 )( =+

    kgt

    kgt

    kek

    ev

    2

    21

    +

    =

    1

    1

    1

    1

    1

    1

    1

    7

    Any correct separation

    Correct A & B

    His correct integration

    base on his A&BCorrect subst.

    Correct subs. for

    finding c

    Get rid of ln

    CA

    7(a)

    (b)

    !! 21

    221

    =ee

    4 e - 2

    e = 0e (4 - ) = 0e 0, = 4

    P(X > 3) = 1 [P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)]

    = 1 -

    +++

    !! 3

    4

    2

    441

    32

    4e

    = 0.5666

    1

    1

    1

    1

    1

    5

    Forming correctequation

    CA

    Complement

    At least 3 correct terms

    with his .

    CA

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    8

    8

    (a)

    (b)

    P(X) =7

    2, P(X Y) =

    21

    1

    P(X|Y) =7

    3

    7

    3=

    )'(

    )'(

    YP

    YXP

    P(X ) P(X Y) =7

    3[1 P(Y)]

    [ ])(YP= 17

    3

    21

    1

    7

    2

    P(Y) =9

    4

    P(X Y) =7

    2+9

    4-21

    1

    = 63

    43

    P(X).P(Y) =7

    2x9

    4=63

    8

    P(X).P(Y) P(X Y)X and Y are not independent events.

    1

    1

    1

    1

    1

    1

    6

    Expansion of P(X|Y)correctly.

    Seen/applied in the

    equation

    Correct formula with his

    value

    CA

    Shown

    7

    2 x9

    4 or his

    value

    Both statements correct

    and

    63

    8 seen

    9(a)

    (b)

    (c)

    m

    0

    5+ m

    1

    5+ m

    2

    5+ m

    3

    5+ m

    4

    5+ m

    5

    5= 1

    m + 5m + 10m + 5m + m = 1

    m =32

    1

    x 0 1 2 3 4 5

    P(X = x)

    32

    1

    32

    5

    32

    10

    32

    10

    32

    5

    32

    1

    E(5X 3) =

    5[0( 32

    1

    )+1(32

    5

    )+2( 32

    10

    )+3( 32

    10

    )+4(32

    5

    )+5( 32

    1

    )] - 3

    =2

    19or 9.5

    1

    1

    1

    1

    11

    1

    7

    At least one of theequation seen

    CA

    At least 4 prob. correctbased on his m.

    All correct with table

    Finding E(X) based on his

    mFor correct usage of

    formula 5E(X) - 3

    CA

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    9

    10

    (a)

    (b)

    (c)

    +

    =

    otherwise,0

    3x,2

    2x,0

    23

    2

    3

    1

    x

    x

    xf )(

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    10

    (c) F = S1 + S2 + S3 + S4 G = L1 + L2 + L3

    Let T = F G

    E(T) = 4(0.760) 3(1.010)

    = 0.01

    Var(T) = 4(0.0082) +3(0.009

    2)

    = 0.000499

    P(T > 0)

    = P

    >

    0004990

    0100

    .

    .Z

    = 0.6728

    1

    1

    1

    1

    1

    10

    Correct linear

    combination(4S-3L isaccepted if his var(T) is

    correct)

    All correct

    All correct

    Standardization based onhis values

    CA

    12

    (a)

    (b)

    120

    7650=

    x

    = 63.75

    2

    120

    7650

    120

    510020

    =

    = 13.64

    20.5 30.5 40.5 50.5 60.5 70.5 80.5 90.5 1 00.5

    0

    10

    20

    30

    40

    50

    60

    70

    80

    90

    100

    110

    120

    Numberofstudents

    Marks

    median = 50564 ..

    105

    16.3

    (i) From the graph, median 50564 ..

    (ii) Range for one deviation from mean for marks

    = [50.11, 77.39]

    Range for one deviation from mean for number of

    students = [14, 107]

    1

    1

    1

    1

    1

    1

    1

    1

    1

    1

    His x 120

    CA

    510020

    Correct formula

    CA

    Boundaries

    Axes & >6 pts correct

    All correct with smoothcurve

    Shown in graph by dotted

    line

    Answer in this range

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    11

    % students in this range = 100120

    16105

    = 74.2%

    1

    1

    12

    Correct formula based on

    his value

    Accept 74% - 78%