Note AcademyNote Academy

Mathematics · May / June 2024 · Paper 31 · Question 6

YMA01

As printed in the paper

The question as text

6. y l P R O x Figure 3 In this question you must show all stages of your working. Solutions relying entirely on calculator technology are not acceptable. Figure 3 shows a sketch of part of the curve with equation y x 4 7 The line l, shown in Figure 3, is the normal to the curve at the point P (8, 5)

Read automatically from the paper; the printed page above is exact.

Show the answer and mark scheme
  • 6(a)[5]

    y

    x

    2

    x

    2

    d

    x

    At (

    )

    −

    1

    2

    8,5 gradient of tangent is (

    )

    2 4 8

    ×−

    7

    =

    2

    5

    5

    (

    )

    Equation for l is

    y

    −

    5

    = −

    x

    −

    8

    2

    2

    *

    y

    −

    10

    = −

    5

    x

    +

    40

    5

    x

    +

    2

    y

    −

    50

    =

    0

    3

    (

    )

    4

    x

    −

    7

    1

    2

    (

    )

    4

    x

    −

    7

    d

    x

    =

    (see notes)

  • 6(b)[4]

    2

    6

    8

    3

    8

    (

    4

    7

    )

    1

    x

    −

    2

    (

    )

    Complete area =

    4

    −

    7

    d

    =

    +

    5

    x

    2

    x

    6

    7

    4

    7

    4

    155

    =

    6

    (a)

    1

    Attempts to differentiate to achieve (

    )

    −

    M1:

    4

    ±

    7

    or equivalent. The index does not need to be

    a

    x

    2

    processed.

    d

    y

    Alternatively, attempts to differentiate implicitly

    2

    =

    4

    −

    7

    =

    y

    x

    Ay

    B

    d

    x

    1

    Achieves (

    )

    −

    A1:

    2 4

    x

    −

    7

    o.e. (which may be unsimplified but the index processed) or using implicit

    2

    d

    y

    differentiation achieves

    2

    y x =

    4

    d

    1

    d

    y

    dM1: Substitutes x = 8 into their (

    4

    7

    )

    −

    a

    x

    ±

    2

    or substitutes y = 5 into their

    x =

    . It does not need to

    Ay

    B

    d

    be evaluated. It is dependent on the first method mark but allow this mark to be scored if they have

    incorrectly manipulated their derivative before substituting in, or made transcription errors

    1

    including if they lose the

    index from the bracket.

    −

    2

    ddM1: A full method for the equation of l. Look for

    substitution of x = 8 (or

    y =

    5

    if implicit differentiation) into an attempt at a derivative

    the application of the negative reciprocal rule
    the use of (

    )

    8,5 with a correct gradient for their value of m to form an equation for the normal.

    5

    1

    −

    5

    = −

    "

    "(

    −

    8)

    with the coordinates in the correct positions. If

    = −

    + is used they must

    y

    x

    y

    x

    c

    2

    m

    c =

    ...

    proceed as far as

    It is dependent on both of the previous two method marks.

    A1*: Correctly achieves 5

    +

    2

    −

    50

    =

    0

    (in any order on the same side of the equation).

    x

    y

    There must be a correct intermediate stage of working following their initial equation for l before

    5

    (

    )

    achieving the given answer, e.g.

    y

    −

    5

    = −

    x

    −

    8

    2

    y

    −

    10

    = −

    5

    x

    +

    40

    5

    x

    +

    2

    y

    2

    (b)

    Note that if no integration is seen then 0 marks.

    3

    Integrates to achieve a correct form (

    )

    4

    x ±

    7

    M1:

    b

    2

    o.e. (the index does not need to be processed)

    1

    u

    2

    3

    May use substitution e.g.

    =

    4

    ±

    7

    d

    (the integral must be correct but allow a slip

    u

    x

    u

    Qu

    2

    4

    on the coefficient for the integrated expression)

    3

    Correct integration (

    )

    4

    x −

    7

    2

    A1:

    (which may be unsimplified) with or without a constant of integration.

    6

    Condone poor notation e.g. if the integral sign and/or dx is still present. Index needs to be processed.

    3

    u

    2

    Using the substitution method score for e.g.

    where

    u

    =

    4

    x

    −

    7

    6

    dM1: Full method to find the shaded area. Note the area of the triangle is 1

    2 ×

    (10

    −

    8) 5

    ×

    =

    8

    3

    (

    )

    Look for

    b

    4

    x

    ±

    7

    2

    +

    5

    o.e. (Provided this is seen then it is sufficient to proceed to the answer)

    7

    4

    The limits must be correct for the integration

    May see integration used for the triangle

    8

    10

    5

    8

    5

    10

    1

    3

    (

    )

    (

    )

    2

    e.g.

    4

    x

    ±

    7

    d

    x

    +

    −

    x

    +

    25

    d

    x

    b

    4

    x

    ±

    7

    + −

    x

    +

    25

    x

    2

    2

    2

    4

    7

    7

    8

    8

    4

    4

    It is dependent on the previous method mark, but you do not need to see the limits substituted in.

    If they do not use the given equation of the straight line l then this mark cannot be scored.

    Condone poor notation provided the intention is clear.

    25

    3

    u

    2

    If using the substitution you may see e.g.

    +5 (send to review if unsure)

    6

    0

    155

    5

    A1:

    6 or exact equivalent e.g.

    25 6 or 25.83

    provided all the previous marks have been scored.

    (

    )

    (

    )

    2 sin

    +

    45

    °=

    cos

    −

    60

    °

Make a free account to save your answers and see your weak topics and ask the AI why a wrong answer is wrong.