msa 1 revision package 2012 solutions

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  • 8/2/2019 MSA 1 Revision Package 2012 Solutions

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    MSA 1 Revision Package 2012 Solutions

    Chapter 1: Partial Fractions, Surds, Indices, Trigonometry Solutions

    1(a) 2

    3 1 3 1

    2 1 (2 1)( 1)

    x x

    x x x x

    + += +

    =2 1 1

    A B

    x x+

    +

    Using Cover-Up Rule,

    13( ) 1

    121 3

    12

    A

    += =

    ,

    3(1) 1 4

    2(1) 1 3B

    += =

    +

    .

    2

    3 1 1 1 4

    2 1 3 2 1 1

    x

    x x x x

    + = + +

    (b)2

    2 2

    2 5 15

    (2 )(1 2 ) 2 1 2

    x x A Bx C

    x x x x

    + + += +

    + +

    Using Cover-Up Rule,2

    2

    2 5(2) 15(2)

    1 2(2)A

    + +=

    += 8.

    2 22 5 15 (1 2 ) ( )(2 )x x A x Bx C x+ + = + + +

    0 : 2 2 3x A C C= = + =

    : 5 2 1x B C B= =

    2

    2 2

    2 5 15 8 3

    (2 )(1 2 ) 2 1 2

    x x x

    x x x x

    + + = + + +

    (c)2

    2 2

    2 1

    (1 ) 1

    x x A B C

    x x x x x

    += + +

    Using Cover-Up Rule,2

    2

    2(1) 1 12

    1C

    += =

    2 22 1 (1 )x x Ax B x Cx + = + +

    1

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    0 :1

    : 1 0

    x B

    x A B A

    = = =

    2

    2 2

    2 1 1 2

    (1 ) 1

    x x

    x x x x

    + = +

    (d)

    23 23 45 14 453

    ( 3) ( 3)

    14 45

    ( 3) 3

    x x x

    x x x x

    x A B

    x x x x

    + + += +

    + ++

    = ++ +

    Using Cover-Up Rule,45 14( 3) 45

    15, 13 3

    A B +

    = = = =

    23 23 45 15 13

    ( 3) 3

    x x

    x x x x

    + + = +

    + +.

    (e)

    3

    3 2

    2 2

    2 16

    28 ( 2)( 2 4)

    ( 2)( 2 4) 2 2 4

    x x x

    x x x x

    x A Bx C

    x x x x x x

    = + +

    += +

    + + + +

    Using Cover-Up Rule,

    2

    2

    2

    3

    3 2

    2 1

    2 2(2) 4 6

    ( 2 4) ( )( 2)

    10 : 0 4 2 2

    3

    1: 0

    6

    2 16 1 1 22

    8 6 2 2 4

    A

    x A x x Bx C x

    x A C C A

    x A B B A

    x x x

    x x x x

    = =+ +

    = + + + +

    = = = =

    = + = =

    = + + +

    (f)

    2

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    3

    2 2 2 2 2

    3 2

    3

    2

    0

    3

    2 2 2 2 2

    3 1

    ( 1) 1 ( 1)

    3 1 ( )( 1)

    : 3

    : 0

    : 0 3

    :1 1

    3 1 3 1 3

    ( 1) 1 ( 1)

    x Ax B Cx D

    x x x

    x Ax B x Cx D

    x A

    x B

    x A C C

    x B D D

    x x x

    x x x

    + + += +

    + + +

    + = + + + +

    =

    == + =

    = + =

    + = +

    + + +

    2 is obtuse, so cos and tan are both negative.

    (a) 1sincos 22 =+ 1cos 22 =+ x

    22 1cos x=

    21cos x=

    (b)21cos

    sintan

    x

    x

    ==

    (c)

    212

    cossin22sin

    xx ==

    (d)

    2

    22

    22

    21

    1

    sincos2cos

    x

    xx

    =

    =

    =

    3(a)

    ( ) ( )

    ( )4

    2 2 2 2 2 2

    2 2 2 2 2 2

    2 2 2

    2

    + = +

    =

    =

    3

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    3(b)( ) ( )

    ( ) ( )

    ( ) ( )

    2

    10 51 10 51

    10 51 2 10 51 10 51 10 51

    20 2 10 51 10 51

    20 2 (100 51)

    6

    +

    = + + +

    = +

    =

    =

    3(c) 1125 175 28

    20

    15 5 5 7 2 7

    2 5

    15 5 3 7 510

    515 3 7

    10

    + +

    = + +

    = + +

    = +

    4 2 5 2 2 5 2 5 2

    5 2 5 2 5 2

    10 10 2 10 2

    5 2

    12 3 103

    4 10

    + + +=

    +

    + + +=

    +=

    = +

    g

    4, 10a b = =

    4

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    Chapter 2: Binomial Expansion Solutions

    1 [NJC/2006/CT/1]

    ( )

    ( ) ( )

    ( ) ( )

    2

    22

    2

    2

    2 2

    2

    2

    22

    5 1f

    1 21 2

    ( 2) 5( 2) 1By cover-up rule, 1.

    ( 2) 1

    5 1 ( )( 2) ( 1)

    Compare coeff. of

    :1 1 2.

    :5 2 5 4 1.

    5 1 2 1 1.

    1 21 2

    x x Ax B Cx

    x xx x

    C

    x x Ax B x x

    x A A

    x A B B

    x x x

    x xx x

    + + += = +

    + ++ + + +

    = = +

    + + = + + +

    = == + = =

    + + + =

    + ++ +

    2 1 1 1

    2

    2 3

    2

    2 33 2

    2 3

    2 1 1f ( ) (2 1)(1 ) 2 (1 )

    1 2 2

    1 ( 1)( 2) ( 1)( 2)( 3)(2 1)(1 ...) (1 ...)

    2 2 2! 2 3! 2

    1( 2 2 1) 1

    2 2 4 8

    1 9 9 31 .2 4 8 16

    x xx x x

    x x

    x x xx x

    x x xx x x

    x x x

    += = + + ++ +

    = + + + + +

    + + +

    = +

    2Validity : 1 and 12

    1 and 2

    1 1 1

    xx

    x x

    x x