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A2 Mathematics (Maths) Core three (C3) Solution Bank answers chapter 1

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Aristotle defined mathematics as:The science of quantity.In Aristotle's classification of the sciences, discrete quantities were studied by arithmetic, continuous quantities by geometry.[1]Auguste Comte's definition tried to explain the role of mathematics in coordinating phenomena in all other fields:[2]The science of indirect measurement.[3] Auguste Comte 1851The "indirectness" in Comte's definition refers to determining quantities that cannot be measured directly, such as the distance to planets or the size of atoms, by means of their relations to quantities that can be measured directly.[4]Greater abstraction and competing philosophical schools[edit]The preceding kinds of definitions, which had prevailed since Aristotle's time,[1] were abandoned in the 19th century as new branches of mathematics were developed, which bore no obvious relation to measurement or the physical world, such as group theory, projective geometry,[3] and non-Euclidean geometry.[5] As mathematicians pursued greater rigor and more-abstract foundations, some proposed definitions purely in terms of logic:Mathematics is the science that draws necessary conclusions.[6] Benjamin Peirce 1870All Mathematics is Symbolic Logic.[5] Bertrand Russell 1903Peirce did not think that mathematics is the same as logic, since he thought mathematics makes only hypothetical assertions, not categorical ones.[7] Russell's definition, on the other hand, expresses the logicist philosophy of mathematics[8] without reservation. Competing philosophies of mathematics put forth different definitions.Opposing the completely deductive character of logicism, intuitionism emphasizes the construction of ideas in the mind. Here is an inituitionist definition:[8]Mathematics is mental activity which consists in carrying out, one after the other, those mental constructions which are inductive and effective.meaning that by combining fundamental ideas, one reaches a definite result.Formalism denies both physical and mental meaning to mathematics, making the symbols and rules themselves the object of study.[8] A formalist definition:Mathematics is the manipulation of the meaningless symbols of a first-order language according to explicit, syntactical rules.Still other approaches emphasize pattern, order, or structure. For example:Mathematics is the classification and study of all possible patterns. Walter Warwick Sawyer, 1955Yet another approach makes abstraction the defining criterion:Mathematics is a broad-ranging field of study in which the properties and interactions of idealized objects are examined. Wolfram MathWorldDefinitions in nonspecialist reference works[edit]Most contemporary reference works define mathematics mainly by summarizing its main topics and methods:The abstract science which investigates deductively the conclusions implicit in the elementary conceptions of spatial and numerical relations, and which includes as its main divisions geometry, arithmetic, and algebra. Oxford English Dictionary, 1933The study of the measurement, properties, and relationships of quantities and sets, using numbers and symbols. American Heritage Dictionary, 2000The science of structure, order, and relation that has evolved from elemental practices of counting, measuring, and describing the shapes of objects.[9] Encyclopaedia BritannicaMathematics is about making up rules and seeing what happens.[10] Vi HartPlayful, metaphorical, and poetic definitions[edit]Bertrand Russell wrote this famous tongue-in-cheek definition, describing the way all terms in mathematics are ultimately defined by reference to undefined terms:The subject in which we never know what we are talking about, nor whether what we are saying is true.[11] Bertrand Russell 1901Many other attempts to characterize mathematics have led to humor or poetic prose:A mathematician is a blind man in a dark room looking for a black cat w
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  • Solutionbank Edexcel AS and A Level Modular Mathematics Exercise A, Question 1

    Question: Simplify:

    (a)

    (b)

    (c)

    (d)

    (e)

    (f)

    (g)

    (h)

    (i)

    (j)

    (k)

    4x + 4x + 1

    2x 16x 3

    x + 4x + 2

    x + 12

    4x + 2

    4x + 2y6x + 3y

    a + 3a + 6

    5p 5q10p 10q

    a + b12

    2a + 4b

    x2

    x2 + 3x

    x2 3xx2 9

    x2 + 5x + 4x2 + 8x + 16

    Page 1 of 4Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_a_1.html

  • (l)

    (m)

    (n)

    (o)

    (p)

    (q)

    (r)

    x3 2x2

    x2 4

    x2 4

    x2 + 4

    x + 2

    x2 + 5x + 6

    2x2 5x 32x2 7x 4

    x2 + x 412

    x2 + x + 214

    32

    3x2 x 2

    x + 12

    13

    x2 5x 6

    x 213

    Solution:

    (a)

    (b)

    (c) will not simplify any further

    (d)

    (e)

    x + 4x + 2

    Page 2 of 4Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_a_1.html

  • (f) will not simplify any further

    (g)

    (h)

    (i)

    (j)

    (k)

    (l)

    (m) will not simplify any further. The denominator doesn't factorise.

    (n)

    (o)

    (p)

    a + 3a + 6

    x2 4

    x2 + 4

    Page 3 of 4Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_a_1.html

  • Pearson Education Ltd 2008

    (q)

    (r)

    Page 4 of 4Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_a_1.html

  • Solutionbank Edexcel AS and A Level Modular Mathematics Exercise B, Question 1

    Question: Simplify:

    (a)

    (b)

    (c)

    (d)

    (e)

    (f)

    (g) x + 2

    (h)

    (i)

    (j)

    (k)

    (l)

    a

    da

    c

    a2

    c

    c

    a

    2x

    x

    4

    3x

    6x

    4xy

    x

    y

    2r2

    54

    r3

    1

    x2 4

    1

    a2 + 6a + 9

    a2 92

    x2 3xy2 + y

    y + 1x

    yy + 3

    y2

    y2 + 4y + 3

    x2

    32x3 6x2

    x2 3x

    4x2 254x 10

    2x + 58

    Page 1 of 3Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_b_1.html

  • (m)

    (n)

    (o)

    x + 3x2 + 10x + 25

    x2 + 5xx2 + 3x

    3y2 + 4y 410

    3y + 615

    x2 + 2xy + y2

    24

    ( x y ) 2

    Solution:

    (a) = =

    (b)

    (c)

    (d)

    (e)

    (f)

    (g)

    (h)

    (i)

    a

    da

    c

    a a

    d ca2

    cd

    Page 2 of 3Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_b_1.html

  • Pearson Education Ltd 2008

    (j)

    (k)

    (l)

    (m)

    (n)

    (o)

    Page 3 of 3Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_b_1.html

  • Solutionbank Edexcel AS and A Level Modular Mathematics Exercise C, Question 1

    Question: Simplify:

    (a) +

    (b) 1

    (c) +

    (d)

    (e) +

    (f) +

    (g)

    (h)

    (i) ( x + 2 ) ( x + 3 )

    (j)

    (k) +

    (l) +

    1p

    1q

    a

    b

    12x

    1x

    3x2

    1x

    34x

    18x

    x

    yyx

    1x + 2

    1x + 1

    2x + 3

    1x 2

    13

    12

    3x( x + 4 ) 2

    1( x + 4 )

    12 ( x + 3 )

    13 ( x 1 )

    2

    x2 + 2x + 1

    1x + 1

    Page 1 of 5Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_c_1.html

  • (m)

    (n)

    (o) +

    (p)

    (q) +

    3x2 + 3x + 2

    2

    x2 + 4x + 4

    2

    a2 + 6a + 93

    a2 + 4a + 3

    2

    y2 x23

    y x

    x + 2

    x2 x 12

    x + 1

    x2 + 5x + 6

    3x + 1( x + 2 ) 3

    2

    ( x + 2 ) 24

    ( x + 2 )

    Solution:

    (a) + = + =

    (b) 1 = = =

    (c) + = + = =

    (d) = =

    (e) + = + =

    (f) + = + =

    (g) = =

    =

    1p

    1q

    qpq

    ppq

    q + ppq

    a

    ba

    b11

    a

    bbb

    a bb

    12x

    1x

    12x

    22x

    1 + 22x

    32x

    3x2

    1x

    3x2

    x

    x23 x

    x2

    34x

    18x

    68x

    18x

    78x

    x

    yyx

    x2

    xyy2

    xyx2 + y2

    xy

    1( x + 2 )

    1( x + 1 )

    x + 1( x + 2 ) ( x + 1 )

    x + 2( x + 2 ) ( x + 1 )

    ( x + 1 ) ( x + 2 ) ( x + 2 ) ( x + 1 )

    1( x + 2 ) ( x + 1 )

    Page 2 of 5Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_c_1.html

  • (h) = =

    =

    (i) ( x + 2 ) ( x + 3 ) = = =

    (j) = = =

    (k) +

    = +

    =

    =

    (l) +

    = +

    = +

    =

    =

    (m)

    =

    =

    2( x + 3 )

    1( x 2 )

    2 ( x 2 ) ( x + 3 ) ( x 2 )

    ( x + 3 ) ( x + 3 ) ( x 2 )

    x 7( x + 3 ) ( x 2 )

    13

    12

    x + 23

    x + 32

    2 ( x + 2 ) 6

    3 ( x + 3 ) 6

    x 56

    3x( x + 4 ) 2

    1( x + 4 )

    3x( x + 4 ) 2

    x + 4

    ( x + 4 ) 23x ( x + 4 )

    ( x + 4 ) 22x 4

    ( x + 4 ) 2

    12 ( x + 3 )

    13 ( x 1 )

    3 ( x 1 ) 6 ( x + 3 ) ( x 1 )

    2 ( x + 3 ) 6 ( x + 3 ) ( x 1 )

    3 ( x 1 ) + 2 ( x + 3 ) 6 ( x + 3 ) ( x 1 )

    5x + 36 ( x + 3 ) ( x 1 )

    2

    x2 + 2x + 1

    1x + 1

    2

    ( x + 1 ) 21

    ( x + 1 )

    2

    ( x + 1 ) 2x + 1

    ( x + 1 ) 2

    2 + x + 1

    ( x + 1 ) 2

    x + 3( x + 1 ) 2

    3x2 + 3x + 2

    2

    x2 + 4x + 43

    ( x + 1 ) ( x + 2 ) 2

    ( x + 2 ) 2

    3 ( x + 2 ) ( x + 1 ) ( x + 2 ) 2

    2 ( x + 1 ) ( x + 1 ) ( x + 2 ) 2

    Page 3 of 5Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_c_1.html

  • =

    =

    (n)

    =

    =

    =

    =

    (o) +

    = +

    = +

    =

    =

    (p)

    =

    =

    =

    =

    3 ( x + 2 ) 2 ( x + 1 ) ( x + 1 ) ( x + 2 ) 2

    x + 4

    ( x + 1 ) ( x + 2 ) 2

    2

    a2 + 6a + 93

    a2 + 4a + 3

    2

    ( a + 3 ) 23

    ( a + 1 ) ( a + 3 )

    2 ( a + 1 ) ( a + 1 ) ( a + 3 ) 2

    3 ( a + 3 ) ( a + 1 ) ( a + 3 ) 2

    2 ( a + 1 ) 3 ( a + 3 ) ( a + 1 ) ( a + 3 ) 2

    a 7

    ( a + 1 ) ( a + 3 ) 2

    2

    y2 x23

    y x

    2( y + x ) ( y x )

    3( y x )

    2( y + x ) ( y x )

    3 ( y + x ) ( y + x ) ( y x )

    2 + 3 ( y + x ) ( y + x ) ( y x )

    2 + 3y + 3x( y + x ) ( y x )

    x + 2

    x2 x 12

    x + 1

    x2 + 5x + 6x + 2

    ( x 4 ) ( x + 3 ) x + 1

    ( x + 3 ) ( x + 2 ) ( x + 2 ) ( x + 2 )

    ( x + 2 ) ( x + 3 ) ( x 4 ) ( x + 1 ) ( x 4 )

    ( x + 2 ) ( x + 3 ) ( x 4 ) ( x2 + 4x + 4 ) ( x2 3x 4 )

    ( x + 2 ) ( x + 3 ) ( x 4 ) 7x + 8

    ( x + 2 ) ( x + 3 ) ( x 4 )

    Page 4 of 5Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_c_1.html

  • Pearson Education Ltd 2008

    (q) +

    = +

    =

    =

    3x + 1( x + 2 ) 3

    2

    ( x + 2 ) 24

    ( x + 2 )

    3x + 1( x + 2 ) 3

    2 ( x + 2 ) ( x + 2 ) 3

    4 ( x + 2 ) 2( x + 2 ) 3

    ( 3x + 1 ) ( 2x + 4 ) + 4 ( x2 + 4x + 4 ) ( x + 2 ) 3

    4x2 + 17x + 13( x + 2 ) 3

    Page 5 of 5Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_c_1.html

  • Solutionbank Edexcel AS and A Level Modular Mathematics Exercise D, Question 1

    Question: Express the following improper fractions in mixed number form by: (i) using long division, (ii) using the remainder theorem

    (a)

    (b)

    (c)

    (d)

    (e)

    (f)

    (g)

    (h)

    (i)

    x3 + 2x2 + 3x 4x 1

    2x3 + 3x2 4x + 5x + 3

    x3 8x 2

    2x2 + 4x + 5x2 1

    8x3 + 2x2 + 52x2 + 2

    4x3 5x2 + 3x 14x2 + 2x 1

    x4 + 3x2 4x2 + 1

    x4 1x + 1

    2x4 + 3x3 2x2 + 4x 6x2 + x 2

    Solution:

    (a) (i)

    Page 1 of 8Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_d_1.html

  • (ii) Let x3 + 2x2 + 3x 4 ( Ax2 + Bx + C ) ( x 1 ) + R

    Let x = 1 1 + 2 + 3 4 = ( A + B + C ) 0 + R 2 = R

    Equate terms in x3 1 = A

    Equate terms in x2 2 = A + B (substitute A = 1) 2 = 1 + B B = 3

    Equate constant terms 4 = C + R (substitute R = 2) 4 = C + 2 C = 6

    Hence x2 + 3x + 6 +

    (b) (i)

    (ii) Let 2x3 + 3x2 4x + 5 ( Ax2 + Bx + C ) ( x + 3 ) + R

    Let x = 3 2 27 + 3 9 + 12 + 5 = ( 9A 3B + C ) 0 + R 10 = R

    Equate terms in x3 2 = A

    x3 + 2x2 + 3x 4x 1

    2x 1

    Page 2 of 8Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_d_1.html

  • Equate terms in x2 3 = B + 3A (substitute A = 2) 3 = B + 6 B = 3

    Equate constant terms 5 = 3C + R (substitute R = 10) 5 = 3C 10 3C = 15 C = 5

    Hence 2x2 3x + 5

    (c) (i)

    (ii) Let x3 8 ( Ax2 + Bx + C ) ( x 2 ) + R

    Let x = 2 8 8 = ( 4A + 2B + C ) 0 + R 0 = R

    Equate terms in x3 1 = A

    Equate terms in x2 0 = B 2A (substitute A = 1) 0 = B 2 B = 2

    Equate constant terms 8 = 2C + R (substitute R = 0) 2C = 8 C = 4

    Hence x2 + 2x + 4

    There is no remainder. So ( x 2 ) is a factor.

    2x3 + 3x2 4x + 5x + 3

    10x + 3

    x3 8x 2

    Page 3 of 8Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_d_1.html

  • (d) (i)

    4x + 7 is less than ( x2 1 ) so it is the remainder.

    (ii) Let

    If the divisor is quadratic then the remainder can be linear. Equate terms in x2 2 = A

    Equate terms in x 4 = B Equate constant terms 5 = A + C (substitute A = 2) 5 = 2 + C C = 7

    Hence 2 +

    (e) (i)

    (ii) Let 8x3 + 2x2 + 5 ( Ax + B ) ( 2x2 + 2 ) + Cx + D

    Equate terms in x3 8 = 2A A = 4

    Equate terms in x2 2 = 2B B = 1

    Equate terms in x 0 = 2A + C (substitute A = 4) 0 = 8 + C

    2x2 + 4x + 5x2 1

    4x + 7

    x2 1

    Page 4 of 8Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_d_1.html

  • C = 8 Equate constant terms 5 = 2B + D (substitute B = 1) 5 = 2 + D D = 3

    Hence 4x + 1 +

    (f) (i)

    (ii) Let 4x3 5x2 + 3x 14 ( Ax + B ) ( x2 + 2x 1 ) + Cx + D

    Equate terms in x3 4 = A

    Equate terms in x2 5 = B + 2A (substitute A = 4) 5 = B + 8 B = 13

    Equate terms in x 3 = A + 2B + C (substitute A = 4, B = 13) 3 = 4 + ( 26 ) + C C = 33

    Equate constant terms 14 = B + D (substitute B = 13) 14 = 13 + D D = 27

    Hence 4x 13 +

    (g) (i)

    8x3 + 2x2 + 52x2 + 2

    8x + 32x2 + 2

    4x3 5x2 + 3x 14x2 + 2x 1

    33x 27x2 + 2x 1

    Page 5 of 8Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_d_1.html

  • (ii) Let x4 + 3x2 4 ( Ax2 + Bx + C ) ( x2 + 1 ) + Dx + E

    Equate terms in x4 1 = A

    Equate terms in x3 0 = B

    Equate terms in x2 3 = A + C (substitute A = 1) 3 = 1 + C C = 2

    Equate terms in x 0 = B + D (substitute B = 0) 0 = 0 + D D = 0

    Equate constant terms 4 = C + E (substitute C = 2) 4 = 2 + E E = 6

    Hence x2 + 2

    (h) (i)

    There is no remainder so ( x + 1 ) is a factor of x4 1.

    (ii) Let x4 1 ( Ax3 + Bx2 + Cx + D ) ( x + 1 ) + E

    x4 + 3x2 4x2 + 1

    6x2 + 1

    Page 6 of 8Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_d_1.html

  • Let x = 1 ( 1 ) 4 1 = ( A + B C + D ) 0 + E E = 0

    Equate terms in x4 1 = A

    Equate terms in x3 0 = A + B (substitute A = 1) 0 = 1 + B B = 1

    Equate terms in x2 0 = B + C (substitute B = 1) 0 = 1 + C C = 1

    Equate terms in x 0 = D + C (substitute C = 1) 0 = D + 1 D = 1

    Hence x3 x2 + x 1

    (i) (i)

    (ii) Let 2x4 + 3x3 2x2 + 4x 6 ( Ax2 + Bx + C ) ( x2 + x 2 ) + Dx + E

    Equate terms in x4 2 = A

    Equate terms in x3 3 = A + B (substitute A = 2) 3 = 2 + B B = 1

    Equate terms in x2 2 = 2A + B + C (substitute A = 2, B = 1) 2 = 4 + 1 + C

    x4 1x + 1

    Page 7 of 8Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_d_1.html

  • Pearson Education Ltd 2008

    C = 1 Equate terms in x 4 = C 2B + D (substitute C = 1, B = 1) 4 = 1 2 + D D = 5

    Equate constant terms 6 = 2C + E (substitute C = 1) 6 = 2 + E E = 4

    Hence 2x2 + x + 1 + 2x4 + 3x3 2x2 + 4x 6

    x2 + x 25x 4

    x2 + x 2

    Page 8 of 8Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_d_1.html

  • Solutionbank Edexcel AS and A Level Modular Mathematics Exercise D, Question 2

    Pearson Education Ltd 2008

    Question: Find the value of the constants A, B, C, D and E in the following identity: 3x4 4x3 8x2 + 16x 2 ( Ax2 + Bx + C ) ( x2 3 ) + Dx + E Solution:

    3x4 4x3 8x2 + 16x 2 ( Ax2 + Bx + C ) ( x2 3 ) + Dx + E

    Equate terms in x4 3 = A

    Equate terms in x3 4 = B

    Equate terms in x2 8 = 3A + C (substitute A = 3) 8 = 9 + C C = 1

    Equate terms in x 16 = 3B + D (substitute B = 4) 16 = 12 + D D = 4

    Equate constant terms 2 = 3C + E (substitute C = 1) 2 = 3 + E E = 1

    Hence 3x4 4x3 8x2 + 16x 2 ( 3x2 4x + 1 ) ( x2 3 ) + 4x + 1 A good idea in equalities is to check with an easy value of x because it should be true for all values of x. Substitute x = 1 into LHS 3 4 8 + 16 2 = 5

    Substitute x = 1 into RHS 3 4 + 1 1 3

    + 4 + 1 = 0 2 + 4 + 1 = 5

    Page 1 of 1Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_d_2.html

  • Solutionbank Edexcel AS and A Level Modular Mathematics Exercise E, Question 1

    Question: Simplify the following fractions:

    (a)

    (b)

    (c)

    (d)

    (e)

    (f)

    abc

    c2

    a2

    x2 + 2x + 14x + 4

    x2 + x

    2x + 1

    4

    x + 21x

    x 1

    a + 4a + 8

    b2 + 4b 5b2 + 2b 3

    Solution:

    (a)

    (b)

    (c)

    (d)

    Page 1 of 2Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_e_1.html

  • Pearson Education Ltd 2008

    (e) doesn't simplify as there are no common factors.

    (f)

    a + 4a + 8

    Page 2 of 2Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_e_1.html

  • Solutionbank Edexcel AS and A Level Modular Mathematics Exercise E, Question 2

    Question: Simplify:

    (a) +

    (b)

    (c)

    (d)

    (e)

    (f)

    x

    4x

    3

    4y

    32y

    x + 12

    x 23

    x2 5x 6x 1

    x3 + 7x 1x + 2

    x4 + 3x2 + 1

    Solution:

    (a) + = + =

    (b) = =

    (c) = = =

    (d) = No common factors so divide.

    x

    4x

    33x12

    4x12

    7x12

    4y

    32y

    82y

    32y

    52y

    x + 12

    x 23

    3 ( x + 1 ) 6

    2 ( x 2 ) 6

    3 ( x + 1 ) 2 ( x 2 ) 6

    x + 76

    x2 5x 6x 1

    ( x 6 ) ( x + 1 ) ( x 1 )

    Page 1 of 2Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_e_2.html

  • Pearson Education Ltd 2008

    Hence = x 4

    (e)

    Hence = x2 2x + 11

    (f)

    Hence = x2 1 +

    x2 5x 6x 1

    10x 1

    x3 + 7x 1x + 2

    x3 + 7x 1x + 2

    23x + 2

    x4 + 3x2 + 1

    x4 + 3x2 + 1

    4

    x2 + 1

    Page 2 of 2Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_e_2.html

  • Solutionbank Edexcel AS and A Level Modular Mathematics Exercise E, Question 3

    Pearson Education Ltd 2008

    Question: Find the value of the constants A, B, C and D in the following identity: x3 6x2 + 11x + 2 ( x 2 ) ( Ax2 + Bx + C ) + D Solution:

    x3 6x2 + 11x + 2 ( x 2 ) ( Ax2 + Bx + C ) + D

    Let x = 2 8 24 + 22 + 2 = 0 ( 4A + 2B + C ) + D D = 8

    Equate coefficients in x3 1 = A

    Equate coefficients in x2 6 = 2A + B (substitute A = 1) 6 = 2 + B B = 4

    Equate coefficients in x 11 = C 2B (substitute B = 4 ) 11 = C + 8 C = 3

    Hence x3 6x2 + 11x + 2 = ( x 2 ) ( x2 4x + 3 ) + 8 Check. Equate constant terms: 2 = 2 3 + 8

    Page 1 of 1Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_e_3.html

  • Solutionbank Edexcel AS and A Level Modular Mathematics Exercise E, Question 4

    Pearson Education Ltd 2008

    Question:

    f ( x ) = x + { x , x > 1 {

    Show that f ( x ) =

    3x 1

    12

    x2 + 2x 3

    x2 + 3x + 3x + 3

    Solution:

    f ( x ) = x +

    = +

    = +

    =

    =

    =

    = [Factorise numerator. ( x 1 ) is a factor as f ( 1 )= 0 .]

    = (cancel common factors)

    =

    3x 1

    12

    x2 + 2x 3x

    13

    x 112

    ( x + 3 ) ( x 1 ) x ( x + 3 ) ( x 1 )

    ( x + 3 ) ( x 1 ) 3 ( x + 3 )

    ( x + 3 ) ( x 1 ) 12

    ( x + 3 ) ( x 1 ) x ( x + 3 ) ( x 1 ) + 3 ( x + 3 ) 12

    ( x + 3 ) ( x 1 ) x ( x2 + 2x 3 ) + 3x + 9 12

    ( x + 3 ) ( x 1 )

    x3 + 2x2 3x + 3x + 9 12( x + 3 ) ( x 1 )

    x3 + 2x2 3( x + 3 ) ( x 1 )

    ( x 1 ) ( x2 + 3x + 3 ) ( x + 3 ) ( x 1 )

    x2 + 3x + 3x + 3

    Page 1 of 1Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_e_4.html

  • Solutionbank Edexcel AS and A Level Modular Mathematics Exercise E, Question 5

    Pearson Education Ltd 2008

    Question:

    Show that x2 + B + for constants B and C, which should be found.

    x4 + 2

    x2 1C

    x2 1

    Solution:

    We need to find B and C such that

    x2 + B +

    Multiply both sides by ( x2 1 ) : x4 + 2 ( x2 + B ) ( x2 1 ) + C x4 + 2 x4 + Bx2 x2 B + C Compare terms in x2 0 = B 1 B = 1

    Compare constant terms 2 = B + C (substitute B = 1) 2 = 1 + C C = 3

    Hence x4 + 2 ( x2 + 1 ) ( x2 1 ) + 3

    So = x2 + 1 +

    x4 + 2

    x2 1C

    x2 1

    x4 + 2

    x2 13

    x2 1

    Page 1 of 1Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_e_5.html

  • Solutionbank Edexcel AS and A Level Modular Mathematics Exercise E, Question 6

    Pearson Education Ltd 2008

    Question:

    Show that can be put in the form Ax2 + Bx + C + . Find the values

    of the constants A, B, C and D.

    4x3 6x2 + 8x 52x + 1

    D2x + 1

    Solution:

    Hence = 2x2 4x + 6 R 11 = 2x2 4x + 6

    So A = 2, B = 4, C = 6 and D = 11

    4x3 6x2 + 8x 52x + 1

    112x + 1

    Page 1 of 1Heinemann Solutionbank: Core Maths 3 C3

    3/9/2013file://C:\Users\Buba\kaz\ouba\c3_1_e_6.html


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