Mathcad - CAPE - 2008 - Math Unit 2 - Paper 02

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  • 7/29/2019 Mathcad - CAPE - 2008 - Math Unit 2 - Paper 02

    1/7

    CAPE 2008 - Pure Mathematics Unit2

    Paper 2

    1 a( ) i( )

    d

    dx e

    4 x

    cos .

    x e

    4 x

    sin .

    x 4 e

    4 x

    cos x.d

    dx e

    4 x

    cos .

    x

    x

    x

    x

    x

    e4 x

    4 cos . x sin . x( )

    ii( )d

    dxln

    x2

    1

    x

    . d

    dxln x

    21.

    d

    dx

    1

    2ln. x( ).

    d

    dxln

    x2

    1

    x

    . d

    dxx

    d

    dxx

    2 x

    x2

    1

    1

    2 x

    3 x2

    1

    2 x x2

    1.

    2 x

    x2

    1

    1

    2 x

    x

    x x

    Alternatively:d

    dxln x

    21. ln x.

    2 x

    x2

    1

    1

    2 x

    d

    dxln x

    21. ln x.

    x

    x x

    3 x2

    1

    2 x x2

    1.

    b( ) ln y. x ln. 3.ln y. x1

    y

    dy

    dxln 3.

    1

    y

    dy

    dx

    dy

    dxy ln. 3.

    dy

    dxy

    dy

    dx3

    xln 3.

    dy

    dx

    x

    c( ) i( )2 x

    23 x 4

    x 1( ) x

    2

    1

    A

    x 1

    Bx C

    x

    2

    1

    Bx C

    x

    Bx

    expands in partial fractions to3

    2 x 1( ).( )

    1

    2

    5 x( )

    x2

    1

    .

    ii( ) x3

    2 x 1( )

    x

    2 x2

    1

    5

    2 x2

    1

    d

    3

    2

    ln x 1( ).1

    4

    ln x2

    1.5

    2

    arctan x( ). C

    2 x2

    3 x 4

    x 1( ) x2

    1

    by integration, yields3

    2ln x 1( ).

    1

    4ln x

    21.

    5

    2arctan x( ). C

    1

  • 7/29/2019 Mathcad - CAPE - 2008 - Math Unit 2 - Paper 02

    2/7

    2 a( ) I e

    x1d x

    I exx

    ex dy

    dx

    . ex

    y e3 x

    ex dy

    dx

    . ex

    yx

    xd

    dxe

    xy. d xe

    3 xdx

    d

    dxe

    xy. d x

    ex

    y1

    3e

    3 xCe

    3 xC

    xy

    1

    3e

    2 x C

    ex

    e2 x

    ex

    x

    x

    b( )

    1

    y

    y1 d

    0

    x

    xe4 x

    d

    1

    y

    y1 d

    x

    y1

    4e

    4 xx

    0

    . 1x

    x

    1

    4e

    4 x3.

    c( )

    1

    e

    xx2

    ln x. dx

    3

    3ln x. e

    1

    .

    1

    e

    xx

    3

    3

    1

    x

    . d

    1

    e

    xx2

    ln x. dx

    x

    x3

    3ln x.

    x3

    9e

    1

    . 1

    92 e

    31

    x3

    3ln x.

    x3

    9e

    1

    .

    d( ) i( ) dv dudv du vv

    1

    2d 2 v. Cv Cv 2 1 u( ). C

    ii( ) du cos x. dx.x dx du 1 sin2

    x dxx dx du 1 u2

    dxu dx

    limits in terms of u are 0, 1

    0

    1

    u

    1 u( )

    1 u2

    d0

    1

    u1 u( )

    1

    2

    d

    0

    1

    u

    1 u( )

    1 u2

    d

    2 1 u( )

    1

    21

    0

    . 22 1 u( )

    1

    21

    0

    .

    2

  • 7/29/2019 Mathcad - CAPE - 2008 - Math Unit 2 - Paper 02

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    Section B (Module 2)

    3 a( ) i( ) u1

    3 u2

    4 u3

    6 u4

    9

    ii( ) let the statement Pn

    n2

    n 6

    2

    n nn

    be assumed true

    P1

    1 1 6

    2P

    13 P

    2

    4 2 6

    2P

    24

    Assume Pn

    is true for n = k Then Pk

    k2

    k 6

    2

    k kk

    Pk 1

    Pk

    kk

    kk

    k2

    k 6

    2 k

    k2

    k 6

    2

    k 1( )2

    k 1( ) 6

    2

    k2

    k 6

    2

    k k

    Since Pk 1

    is of the form of Pk

    for n = k + 1 and

    Pn

    is true for n = 1 Pn

    is true for n = 2 Pn

    is true for all n N

    Alternatively: for n > 1 un

    un 1

    n 1( )n

    nn

    from given defn of un

    un

    un 1

    n 1un

    un 1

    n un 1

    un 2

    n 2un 1

    un 2

    n un 2

    un 3

    n 3un 2

    un 3

    n

    u2

    u1

    1u2

    u1

    un

    u1

    1 2 ... n 1( )... un

    u1

    n

    2n 1( )u

    nu

    1

    nn arith prog

    un

    n

    2n 1( ) 3

    nn

    nu

    n

    n2

    n 6

    2

    n nn

    b( )a

    1 r81

    a

    1 r

    a 1 r4.

    1 r65

    a 1 r4.

    1 r1 r

    4 65

    811 r

    4r

    4 16

    81r

    4r

    2

    3

    a 27

    c( ) i( ) ln 1 x( ). xx

    2

    2

    x3

    3

    x4

    4

    x5

    5......x

    x x x x1 x< 1

    ii( ) a( ) ln 1 x( ). xx

    2

    2

    x3

    3

    x4

    4

    x5

    5ln 1 x( ). x

    x x x x1 x 1