Mathematics 9709/21 May/June 2023: question paper and mark scheme
Cambridge AS & A Level Mathematics (9709), Paper 2 Pure Mathematics 2, May/June 2023. Read both free below, or download them. Done the paper? Get it marked by AI against this mark scheme.
Use logarithms to solve the equation 12x = 32x+1 . Give your answer correct to 3 significant figures.
[4]
2 + 3 ln x
A curve has equation y =
1 + 2x
Mark scheme
1 Apply logarithms to both sides and apply power law correctly at least once *M1 OE with x not in a power.
Obtain x ln12 = (2 x + 1)ln 3 A1
Attempt solution of linear equation DM1
Obtain 3.82 A1 Do not condone incorrect use of logarithms
or greater accuracy.
4
.
Find the equation of the tangent to the curve at the point 1, 32 . Give your answer in the form ax + by + c = 0, where a, b and c are integers. [5]
It is given that Ó 3e2x − 1 dx = 12, where a is a positive constant. a
Mark scheme
2 Use quotient rule (or equivalent) to find first derivative M1
(1 + 2 x) 3x − (2 + 3ln x)2 A1 OE
Obtain 2
(1 + 2 x)
Substitute x = 1 and obtain 59 A1
Attempt equation of tangent through (1, 23 ) with their numerical gradient M1 Must have made an attempt at differentiation.
Obtain 5 x − 9 y + 1 = 0 or equivalent of required form A1
5
0
(a) Show that a = 12 ln 9 + 23 a .
[4]
(b) Use an iterative formula, based on the equation in (a), to find the value of a correct to 4 significant figures. Use an initial value of 1 and give the result of each iteration to 6 significant figures. [3]
Mark scheme
3(a) Integrate to obtain the form k1e2 x + k2 x *M1 Where k1k 2 ≠ 0 .
Obtain correct 3 2x
e −x A1
2
Use limits correctly and attempt rearrangement at least as far as e 2 a = ... DM1 For DM1, must be equated to 12 and simplified using a
correct method. Do not condone verification.
Confirm given result a = 12 ln(9 + 23 a ) with sufficient detail A1 AG
4
3(b) Use iteration process correctly at least once M1 Need to see 1.13434 and 1.13895 .
Obtain final answer 1.139 A1 Final answer needed to exactly 4 sf.
Show sufficient iterations to 6 sf to justify answer or show a sign change in A1
interval [1.1385, 1.1395]
3
The polynomial p x is defined by
p x = 2x3 + 3x2 + kx − 30,
where k is a constant. It is given that x − 3 is a factor of p x.
(a) Find the value of k. [2]
(b) Hence find the quotient when p x is divided by x − 3 and factorise p x completely. [3]
(c) It is given that a is one of the roots of the equation p x = 0.
Given also that the equation 4y − 5 = a is satisfied by two real values of y, find these two values of y. [3]
Mark scheme
4(a) Substitute x = 3 , equate to zero and attempt solution M1 51
Condone − .
3
Obtain k = −17 A1
2
4(b) Divide by x − 3 at least as far as 2 x 2 + mx M1
Obtain 2 x 2 + 9 x + 10 A1
Obtain ( x − 3)(2 x + 5)( x + 2) A1 SC – no attempt at division (or equivalent) and only
correct fully factorised form shown: award B1 only.
3
4(c) Solve linear equation 4 y − 5 = 3 to obtain y = 2 B1 FT following any positive root from their factorised p( x) .
Attempt solution of linear equation 4 y − 5 = −3 or equivalent M1 with RHS of equation being – (their positive root).
Obtain y = 12 A1
Alternative method for Question 4(c)
State or imply (4 y − 5) 2 = 32 B1 FT following any positive root from their factorised p( x) .
Attempt solution of 3-term quadratic equation (4 y − 5) 2 = 32 M1 with RHS of equation involving their positive root.
Obtain 12 and 2 and no other solutions A1
3
y
M
x
O
The diagram shows the curve with parametric equations
x = 4e2t , y = 5e−t cos 2t, for − 14 π ≤ t ≤ 14 π. The curve has a maximum point M .
dy
(a) Find an expression for in terms of t. [3]
dx
(b) Find the coordinates of M , giving each coordinate correct to 3 significant figures. [5]
1π
@ A
Show that Ô 4 cos2 2x + dx = 34 3 + 16 π − 1.
3
1
Mark scheme
5(a) dy M1
Use product rule to find
dt
dy A1 or (unsimplified) equivalent (do not condone poor use of
Obtain = −5e−t cos 2t − 10e−t sin 2t brackets.
dt
dy −5e −t cos 2t − 10e −t sin 2t A1 dy
Obtain = OE following their expression for .
dx 8e 2t dt
3
5(b) dy M1* dx
Equate to zero and simplify at least as far as tan 2t = ... now condoning any error with .
dx dt
Obtain tan 2t = − 12 A1
Obtain t = −0.231... A1 allow t = −0.232 .
Substitute negative value of t in expressions for x and y DM1
Obtain x = 2.52 and y = 5.64 A1 or greater accuracy.
5
6 Express 4cos 2 2x in the form k1 cos 4 x + k2 M1 where k1k 2 ≠ 0 .
Obtain correct 2 cos 4 x + 2 A1 Allow unsimplified.
1 B1 Maybe implied by integration.
State or imply 2
= sec 2 x
cos x
Integrate to obtain k3 sin 4 x + k 4 x + tan x *M1 where k3 k4 ≠ 0 .
Obtain correctly 12 sin 4 x + 2 x + tan x A1
Use limits correctly with correct values of sin 43 π and tan 13 π indicated DM1
Confirm given result 34 3 + 16 π − 1 with sufficient detail A1 AG
7
(a) Express 7 cos 1 + 24 sin 1 in the form R cos 1 − !, where R > 0 and 0Å < ! < 90Å. Give the value of ! correct to 2 decimal places. [3]
(b) Solve the equation 7 cos 1 + 24 sin 1 = 18 for 0Å < 1 < 360Å. [4]
(c) As " varies, the greatest possible value of
150
7 cos 12 " + 24 sin 21 " + 50
is denoted by V .
Find the value of V and determine the smallest positive value of " (in degrees) for which the value of V occurs. [4]
Additional Page
If you use the following lined page to complete the answer(s) to any question(s), the question number(s) must be clearly shown.
Mark scheme
7(a) State R = 25 B1
Use appropriate trigonometry to find α M1 Allow if found in radians .
Obtain α = 73.74 A1 or greater accuracy.
3
7(b) Use correct method to find one value of θ M1
Obtain 29.8 (or 117.7) A1 or greater accuracy.
Use correct method to find second value of θ between 0 and 360 M1
Obtain 117.7 (or 29.8) A1 or greater accuracy; and no others between 0 and 360.
4
7(c) 150 B1 FT following their R and α .
State or imply expression is
25cos( 12 β − 73.74) + 50
Obtain V = 6 B1
Attempt complete method to find positive value from cos( 12 β − 73.74) = −1 M1 for their α .
Obtain 507.5 A1 or greater accuracy.
4
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On this page, free: the mark scheme for AS & A Level Mathematics 9709/21, May/June 2023 (9709_s23_ms_21), and the question paper (9709_s23_qp_21), to read or download, with each question's marking points written out underneath.
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Mathematics 9709/21 for May/June 2023 is out of 50 marks, with 1 hour 15 minutes to answer it.
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