kedah trial stpm 2012-mathst paper 2(q&a)

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  • 7/31/2019 Kedah Trial Stpm 2012-Mathst Paper 2(Q&A)

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    S T P M K E D A H 2 0 1 2 - M T P A P E R 2 C H U / S M K K

    1 P r o v e t h a t ( ) ( ) A A A A 3 s i n

    4 1

    6 0 s i n 6 0 s i n s i n = + . [ 4 m ]

    2 G i v e n A B

    = ( 2 k 1 ) i i i i j j j j a n d A C

    = 6 i i i i + k j j j j a r e t w o v e c t o r s l i e o n a s a m e

    p l a n e . F i n d t h e v a l u e o f k

    ( a ) i f t h e p o i n t s A , B a n d C a r e c o l l i n e a r ,

    ( b ) i f B A C = 9 0 o . [ 4 m ]

    3 T h e d i a g r a m s h o w s a c i r c l e . P Q i s a t a n g e n t t o t h e c i

    s t r a i g h t l i n e P R c u t s t h e c i r c l e a t S . S h o w t h a t

    ( a ) i f R Q S = Q P S , t h e n t h e l e n g t h o f c h o r d Q R i s t w i c e to f t h e c i r c l e ,

    ( b ) i f R Q S = 3 0 o , t h e n t h e l e n g t h o f c h o r d R S i s e q u a l t o t h c i r c l e .

    [ 3 m ]

    [ 3 m ]

    4 F i n d t h e g e n e r a l s o l u t i o n o f t h e d i f f e r e n t i a l e q u a t i o n2 5 0 .

    d y x y y

    d x + =

    D e d u c e t h a t t h e p a r t i c u l a r s o l u t i o n f o r w h i c h y = 1 w he x p r e s s e d i n t h e f o r m a n d s k e t c h t h e c u r v e .

    S k e t c h , i n s e p a r a t e d i a g r a m , t h e s o l u t i o n c u r v e w h i c

    p o i n t ( 1 , 0 ) .

    [ 3 m ]

    [ 2 m ]

    [ 3 m ]

    5 I n a p a r a l l e l o g r a m A B C D , X i s t h e m i d p o i n t o f A B a nd i a g o n a l A C a t P .

    G i v e n t h a t A B = a , a , a , a , A D = = = = b , b , b , b , A P = = = = A C a n d D P = D X , e x p r e s s A P i n t e r m s o f ( a ) , a a a a a n d b b b b . ( b ) , a a a a a n d b b b b . H e n c e , d e d u c e t h a t P i s a p o i n t o f t r i s e c t i o n o f b o t h A

    [ 2 m ] [ 3 m ] [ 5 m ]

    6 E x p r e s s ( c o s x + 1 ) 2 + ( s i n x + 3 ) 2 i n t h e f o r m a + b c o s ( x ) , w h e r e a >

    0 , b > 0 a n d 0 < < 1 2

    . H e n c e ,

    ( a ) f i n d t h e s e t o f v a l u e s o f k s u c h t h a t t h e f o l l o w i n g e

    ( c o s x + 1 ) 2 + ( s i n x + 3 ) 2 = k 2 ,

    [ 4 m ]

    [ 3 m ]

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    ( b ) s o l v e , f o r 0 < x < 2 , t h e e q u a t i o n

    ( c o s x + 1 ) 2 + ( s i n x + 3 ) 2 = 5 + 2 2 ,

    ( c ) f i n d t h e v a l u e s o f p a n d q s u c h t h a t 2 ( c o s x + 1 ) 2 + ( s i n x + 3 ) 2

    l i e s i n

    t h e i n t e r v a l ( p , q ) a n d t h e c o r r e s p o n d i n g v a l u e s o f x .

    [ 3 m ]

    [ 5 m ]

    7 T h e r e s u l t o f a v e t e r i n a r y s u r v e y o n 1 2 5 r a b b i t s , e a cp a r t i c u l a r d i s e a s e i s s u m m a r i z e i n t h e f o l l o w i n g t a b l

    D i s e a s e d N o t D i s e a s e d T o t a l F e m a l e 2 5 3 5 6 0 M a l e 2 0 4 5 6 5 T o t a l 4 5 8 0 1 2 5

    T h e c a s e h i s t o r y o f e a c h r a b b i t w a s k e p t o n a s e p t h r e e d i f f e r e n t r e c o r d c a r d s a r e s e l e c t e d a t r a n d o m

    c a l c u l a t e t h e p r o b a b i l i t y t h a t

    ( a ) a l l t h r e e r e c o r d c a r d s r e l a t e t o r a b b i t s w i t h t h e ( b ) o n e r e c o r d c a r d r e l a t e s t o a f e m a l e r a b b i t w i t h

    m a l e r a b b i t w i t h t h e d i s e a s e a n d o n e t o a f e m a l e r a

    t h e d i s e a s e .

    [ 3 m ]

    [ 3 m ]

    8 T h e p r o b a b i l i t y t h a t a s h o o t e r s t r i k e s a t a r g e t i n o n

    p r o b a b i l i t y t h a t n o t l e s s t h a n t h r e e o f f i v e s h o t s f i r e d ,

    A f t e r t h e s h o o t e r h a s c o m p l e t e d a o n e m o n t h s h

    p r o b a b i l i t y t h a t h e s t r i k e s t h e t a r g e t i n o n e s h o t i s 0 .

    a p p r o x i m a t i o n , f i n d t h e p r o b a b i l i t y t h a t i n a s a m p l e o

    s h o t s s t r i k e t h e t a r g e t .

    [ 3 m ]

    [ 4 m ]

    9 T h r e e r e d b a l l s a n d t h r e e w h i t e b a l l s a r e p l a c e d i n a

    b y o n e , a t r a n d o m a n d w i t h o u t r e p l a c e m e n t . T h e r a

    n u m b e r o f w h i t e b a l l s d r a w n b e f o r e t h e f i r s t r e d b a l l i

    ( a ) S h o w t h a t P ( X = 1 ) = 1 0 3 , a n d f i n d t h e r e s t o f t h e p r o b a b i l i t y d

    f u n c t i o n o f X .

    ( b ) F i n d E ( X ) a n d s h o w t h a t V a r ( X ) = 8 0 6 3

    .

    [ 3 m ]

    [ 4 m ]

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    1 0 T h e t a b l e s h o w s t h e d u r a t i o n s o f 6 0 j o u r n e y s o n t ht h e v a r i a t i o n s i n j o u r n e y t i m e s b e i n g c a u s e d b y v a r y

    C a l c u l a t e , t o t h e n e a r e s t m i n u t e , e s t i m a t e s o f t h e d e v i a t i o n f o r t h e d u r a t i o n o f t h e j o u r n e y s .

    W h e n t h e t i m e s f o r 4 0 o t h e r j o u r n e y s w e r e t a k e n , i t wa n d s t a n d a r d d e v i a t i o n f o r t h e t i m e s o f t h e s e 4 0 j o u

    a n d 1 8 m i n , r e s p e c t i v e l y . F i n d a l s o , t o t h e n e a r e s t mm e a n a n d s t a n d a r d d e v i a t i o n f o r t h e d u r a t i o n o f a l l 1

    T i m e T i m e T i m e T i m e o f o f o f o f j o u r n e y j o u r n e y j o u r n e y j o u r n e y i n i n i n i n h o u r s h o u r s h o u r s h o u r s

    N u m b e r N u m b e r N u m b e r N u m b e r o f o f o f o f j o u r n e y s j o u r n e y s j o u r n e y s j o u r n e y s

    4 . 6 4 . 8 2 4 . 8 5 . 0 7 5 . 0 5 . 2 1 6 5 . 2 5 . 4 2 1 5 . 4 5 . 6 1 2 5 . 6 5 . 8 2

    [ 4 m ]

    [ 5 m ]

    1 1 T h e c o n t i n u o u s r a n d o m v a r i a b l e X i s t h e d i s t a n c e ,

    k i l o m e t e r s , t h a t a p a r t i c u l a r c a r w i l l t r a v e l o n a f u l l t

    t h a t

    = , 1

    , 2 4 1 0

    , 0

    ) ( 2 x x x X P a a

    w h e r e a i s a c o n s t a n t . S h o w t h a t a = 1 . ( a ) F i n d t h e p r o b a b i l i t y d e n s i t y f u n c t i o n o f X .

    ( b ) S h o w t h a t E ( X ) = 3

    1 3 .

    ( c ) T h r e e i n d e p e n d e n t o b s e r v a t i o n s o f X a r e t a k e n .

    t w o o f t h e o b s e r v a t i o n s a r e l e s s t h a n 4 . 5 a n d o n e i s g

    [ 2 m ]

    [ 3 m ]

    [ 3 m ]

    1 2 A f a c t o r y p r o d u c e s b o t h m e t a l r o d s a n d t u b e s . T h e

    o f a m e t a l t u b e i s d i s t r i b u t e d N ( 2 . 2 , 0 . 0 0 0 9 ) . T h e d i a

    r o d i s d i s t r i b u t e d N ( 2 . 1 5 , 0 . 0 0 0 4 ) .

    ( a ) F i n d t h e p e r c e n t a g e o f t u b e s w i t h i n t e r n a l d i a m e( b ) F i n d t h e p e r c e n t a g e o f r o d s w i t h d i a m e t e r g r e a tt h a n 2 . 2 c m . ( c ) A r o d a n d a t u b e a r e c h o s e n a t r a n d o m . F i n d t h e

    w i l l n o t p a s s t h r o u g h t h e t u b e .

    ( d ) T h r e e p a c k e t s , e a c h c o n t a i n i n g a r o d a n d a t u b e

    F i n d t h e p r o b a b i l i t y t h a t t w o p a c k e t s c o n t a i n r o d s t h

    r e s p e c t i v e t u b e s a n d t h e o t h e r w i l l n o t .

    [ 3 m ]

    [ 3 m ]

    [ 5 m ]

    [ 3 m ]

    x

    x

    x

    5

    , 5 4

    , 4

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    S T P M K E D A H 2 0 1 2 - M T P A P E R 1 - M A R K I N G S C H E M E

    1 . 2 x = 3 y

    2 x = 3 1 x

    x l n 2 = ( 1 x ) l n 3

    x ( l n 2 + l n 3 ) = l n 3

    x = l n 3 l n 6

    .

    2 .

    3 .

    2 s e c = d d x

    ,

    t a n 0 = 0 , t a n 4

    = 1

    ( 1 + x 2 ) 2 = ( 1 + t a n 2 ) 2 = s e c 4

    ( ) =

    + 4

    0

    2

    4

    1

    0 2 2 s e c

    s e c

    1

    1

    1

    d x x

    d

    = 4 0 2 c o s

    d

    ( ) ( ) + = +

    1

    0

    4

    0 2 2

    2 c o s 1 2 1

    1

    1

    d d x x

    = 1 2

    4

    0

    1 s i n 2

    2

    +

    B 1

    M 1 A 1

    A 1

    B 1

    M 1

    M 1 A 1

    M 1

    A 1

    A 1

    M 1

    B 1

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    = 1 8

    [ + 2 ] .

    4 .

    5 . c o s 3 = x y a x

    c o s 3 = y x a x

    d x d y

    x x y 3 2 ) ) ( 3 ( + = a x a s i n

    d x

    d y x y x 3 2 3 + = a x a s i n

    ( ) ( ) ( ) ( ) a x a x d x d y

    d x y d

    x x y d x d y

    x c o s 3 2 3 2 2 2 2

    3 2 = + +

    +

    a x a d x d y

    x d x

    y d x x y

    d x d y

    x c o s 3 6 3 2 2 2 2

    3 2 = + + +

    a x a d x y d

    x x y d x d y

    x c o s 6 6 2

    2

    2 3 2

    = + +

    S u b i n t o

    3 2 2

    2 3 2 6 6 y x a

    d x y d

    x x y d x d y

    x = + +

    0 6 6 3 2 2

    2 3 2 = + + + y x a

    d x

    y d x x y

    d x

    d y x

    D 1 : x y =

    D 1 : s h a p e o f 2 = x y

    D 1 : p o i n t s ( 2 , 0 ) , ( 0 , 2

    T h e s o l u t i o n s e t i s } { < < x x x , 4 1 : B 1

    A 1

    1

    2

    1 2

    M 1 A 1

    M 1 A 1

    M 1

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    ( ) 0 6 6 2 2 2 2

    2 =

    + + + y x a y

    d x d y

    x d x

    y d x x

    ( ) 0 6 6 2 2 2 2

    2 = + + + y x a d x d y

    x d x

    y d x

    6 .

    L e t ( ) ( ) 4 :

    4 :

    2

    1

    + = =

    x m y l

    x m y l

    i n t e r c e p t 2 5 5 4 = + y x a t p o i n t F ( x 1 , y 1 ) a n d G ( x 2 , y 2 ) .

    ( ) [ ]

    ( )

    m m

    x

    m m x

    m m x x

    x m x

    5 4 2 0 2 5

    2 0 2 5 5 4

    2 5 2 0 5 4

    2 5 4 5 4

    1

    1

    1 1

    1 1

    + + =

    + = + = + = +

    + + = 4

    5 4 2 0 2 5

    1 m m

    m y

    m m y 5 4

    9 1 +

    =

    + + +

    m m

    m m

    F 5 4

    9 ,

    5 4 2 0 2 5

    ( ) [ ]

    ( )

    m m x

    m m x

    m m x x

    x m x

    5 4 2 0 2 5

    2 0 2 5 5 4

    2 5 2 0 5 4

    2 5 4 5 4

    2

    2

    2 2

    2 2

    + =

    + = + = + = + +

    +

    + = 4

    5 4 2 0 2 5

    2 m m

    m y

    m m

    y 5 4

    4 1 2 +

    =

    + +

    m

    m

    m

    m G

    5 4

    4 1 ,

    5 4

    2 0 2 5

    A 1

    B 1

    ( a ) M 1

    A 1

    A 1

    ( l 1 o r l 2 )

    A 1

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    8 5 4

    4 1 5 4

    9 5 4 2 0 2 5

    5 4 2 0 2 5

    2 2

    =

    +

    + +

    +

    + +

    m m

    m m

    m m

    m m

    2 2 2

    8 5 4

    3 2 5 4

    4 0 =

    + +

    + m m

    m m

    6 4 2 5 4 0 1 6

    2 6 2 4 2

    2

    = + + m m m

    0 1 6 4 0 1 6 2 = + + m m

    0 2 5 2 2 = + + m m

    ( ) ( ) 0 2 1 2 = + + m m

    2 , 2 1 = m

    7 . ( a ) | w | = 4 1 ,

    a r g w = t a n 1 4 5

    = 2 . 4 7 r a d . ( 3 s . f . )

    ( b ) z w

    = 3 + 2 i 5 + 4 i

    x 5 4 i 5 4 i

    = 7 4 1

    2 2 4 1

    i

    ( c ) Z ( 3 , 2 ) , W ( 5 , 4 ) , Z * ( 3 , 2 ) , P ( x , y )

    m i d - p t o f Z Z * = m i d - p t o f W P

    ( 3 , 0 ) = ( x 5 2

    , y + 4 2

    )

    x = 1 1 , y = 4

    p = 1 1 4 i .

    8 .

    ( b )

    M 1

    A 1

    M 1 A 1

    M 1 A 1

    A 1

    A 1

    M 1

    B 1

    5 l n 2 l n x y =

    5 l n 2 1 =

    d x d y

    y

    5 l n 2 y d x d y =

    2 5 l n 5 2 x

    d x

    d y =

    M 1

    A 1

    M 1

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    ( ) 1

    0

    2 2 2 5 l n 5 d x x x

    = ( )

    1

    0

    2 2 5 l n 5 2 5 l n d x x x

    = 1

    0

    2 2 2 5 l n 5 2 5 l n 5

    d x x x x

    = [ ] 1 0 2 2 5 2 5 l n 5 x x x

    = 5 0 l n 5 2 4

    H e n c e , m = 5 0 , n = 2 4

    9 . ( a ) D o m a i n : } { 5 , : = x x x g

    R a n g e : } { 0 , : = y y y g

    ( b ) ( ) 3 ) ( + = x x f g

    ( ) ( ) 3 2

    5 3 2 + = + + x b x a

    ( ) ( ) [ ] 2 2

    3 2

    5 3 + = + + x b x a

    1 2

    = a

    a = 2

    0 2

    5 = + b

    b = 5

    B 1 B 1

    M 1

    M 1 A 1

    A 1 A 1

    B 1

    B 1

    M 1

    A 1

    A 1

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    ( c )

    S i n c e t h e l i n e p a r a l l e l t o t h e x - a x i s i n t e r s e c t s t h e c u r v e y = f i s o n e - t o - o n e f u n c t i o n .

    f ( x ) = 2 ( x + 3 ) 2 5

    2 ( y + 3 ) 2 5 = x

    2 ( y + 3 ) 2 = x + 5

    ( ) 2

    5 3 2

    + = + x y

    2 5

    3 + = + x y

    2

    5 3

    + = + x y

    2 5

    3 + = x y

    5 , 2

    5 3 ) ( 1 + = x x x f

    1 0 .

    =

    +

    +

    2 2 2

    2 5 1 2 2 4

    1 0 0

    0 1 0 0 0 1

    3 2 2

    1 2 1 1 0 1

    3 2 2

    1 2 1 1 0 1

    3 2 2

    1 2 1 1 0 1

    b a

    =

    +

    +

    2 2 2

    2 5 1

    2 2 4

    0 0

    0 0

    0 0

    3 2 2

    2

    0

    9 1 0 1 0

    4 6 5

    4 2 1

    b

    b

    b

    a a a

    a a a

    a a

    =

    + + + + + + + + + +

    2 2 2

    2 5 1 2 2 4

    3 9 2 1 0 2 1 0

    4 2 6 5 4 2 1

    b a a a

    a b a a a b a

    B 1

    S h a p e D 1

    A l l c o r r e c t D 1

    s i n c e 3 y

    M 1

    A 1

    M 1

    A 1

    f ( x )

    x - 3

    - 5

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    6

    1 5

    = = +

    a

    a

    1 1 4 1 = = + + b b a

    ( )

    = + +

    2 2 2

    2 5 1

    2 2 4

    3 2 2

    1 2 1

    1 0 1 2 b I a P P P

    =

    6 0 0

    0 6 0

    0 0 6

    ( ) I b I a P P P 6 2 = + +

    =

    2 2 2

    2 5 1

    2 2 4

    6 1 1 P

    =

    5

    2

    3

    3 2 2

    1 2 1

    1 0 1

    z

    y

    x

    =

    5

    2

    3

    2 2 2

    2 5 1

    2 2 4

    6 1

    z

    y

    x

    =

    0 2 1

    3

    z y x

    0 , 2 1

    , 3 = = = z y x

    A 1

    A 1

    A 1

    B 1

    B 1

    A 1

    M 1

    B 1

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    1 1 .

    ( a )

    ( b )

    C o n s i d e r ,

    S i n c e

    H e n c e

    H e n c e ,

    M 1

    A 1

    M 1 A 1

    A 1

    M 1 A 1

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    1 2 . ( a ) t h e a s y m p t o t e i s x = 5 4 .

    ( b ) f ( x ) = 4 x + 4 4 x + 5

    .

    = 4 ( 4 x + 1 ) ( x + 1 ) 4 x + 5

    f ( x ) = 4 + 4 ( 1 ) ( 4 x + 5 ) 2 ( 4 )

    = 4 ( 4 x + 7 ) ( 4 x + 3 ) ( 4 x + 5 ) 2

    W h e n f ( x ) = 0 , ( x , y ) = ( 1 , 2 ) o r ( 1 4

    , 1 8

    + l n 4 )

    M 1

    A 1

    A 1

    c )

    0 1 1

    6 1

    1 3 1

    1 2 1

    4 2 3 4

    = +

    +

    x x x x

    B 1

    M 1 r e f e r t o ( a )

    A 1

    s i g n o f f

    ( x ) :

    s i g n o f f

    ( x ) :

    1 1 4

    x

    3 4

    + +

    5 4

    + +

    B 1

    M 1 f o r f a n d f

    M 1 A 1 f o r s t a t i o n a r p o i n t s

    M 1 d e t e r m i n e n a t u ro f s t a t i o n a r y p o i n t s

    A 1 f o r f o r f

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    l o c a l m a x i m u m a t ( 1 , 2 )

    l o c a l m i n i m u m a t ( 1 4 , 1 8 + l n 4 )

    ( c ) W h e n f ( x ) = 0 , x = 3 4

    { 7 4

    i s n o t i n t h e g i v e n d o m a i n }

    i n f l e x i o n a t ( 3 4

    , 9 8

    + l n 2 )

    ( e ) m a x i m u m f o c c u r s a t x = 1

    m a x . f i s 2 + l n 9

    A 1

    A 1

    M 1 A 1

    A 1

    B 1

    D 1 f o r s h a p e

    D 1 f o r a s y m p t o t e

    D 1 f o r p o i n t s i n ( b ) & ( c )

    x O

    y

    ( 1 , 2 + l n 9 )

    ( 1

    4 ,

    1

    8 + l n 4 )

    ( 1 , 2 )

    ( 3

    4 ,

    9

    8 + l n 2 )

    4 5 = x

    ( d )