Skill Align VCE Specialist Mathematics Units 3&4 - Free Online Pack 0
Examination 2 showcase | Technology active
- Paper
- Examination 2 Showcase
- Reading
- 15 minutes
- Writing
- 2 hours
- Assessment
- 80 marks
Approved materials: one approved CAS calculator or CAS software, one scientific calculator, one bound reference, protractors, set squares and aids for curve sketching. Use the standard VCE Specialist Mathematics formula sheet available separately.
Section A - Multiple-Choice Questions
For this free online paper, record one response for each question in your own notes or on a separate answer sheet before checking solutions. Choose exactly one answer for each question. A correct answer scores 1 mark; an incorrect or multiple answer scores 0, with no mark deduction.
Question 1
1 mark- 16
- -16
- 16i
- -16i
Question 2
1 mark- costheta=frac49
- costheta=frac29
- costheta=frac13
- costheta=frac89
Question 3
1 mark- 1
- 0
- e
- frac1e
Question 4
1 mark- y=3+2e^(-x)
- y=3-2e^(-x)
- y=5e^(-x)
- y=2+3e^(-x)
Question 5
1 mark- 6
- 3
- 2
- 6t
Question 6
1 mark- 3.92
- 1.96
- 2
- 23.52
Question 7
1 mark- y=-x
- y=x
- x=1
- y=-1
Question 8
1 mark- 8
- -8
- 8i
- -8i
Question 9
1 mark- frac23
- frac43
- 2
- 6
Question 10
1 mark- 3
- 6
- frac32
- 12
Question 11
1 mark- 0
- 1
- frac12
- -frac12
Question 12
1 mark- frac52
- 5
- frac12
- 25
Question 13
1 mark- 18 mathrm(N,s)
- 12 mathrm(N,s)
- 36 mathrm(N,s)
- 6 mathrm(N,s)
Question 14
1 mark- 20 mathrm(m,s⁻²)
- 2 mathrm(m,s⁻²)
- 50 mathrm(m,s⁻²)
- 100 mathrm(m,s⁻²)
Question 15
1 mark- t=frac32
- t=1
- t=2
- t=frac34
Question 16
1 mark- 30 and √21
- 30 and 21
- 70 and √21
- 30 and √30
Question 17
1 mark- frac23
- frac12
- frac13
- frac34
Question 18
1 mark- 2
- 6
- frac23
- 18
Question 19
1 mark- -1
- 1
- i
- -i
Question 20
1 mark- 2.5
- 2.0
- 2.75
- 3.0
Section B - Extended-Response Questions
Answer all questions. Unless otherwise specified, an exact answer is required for each question. In questions where more than one mark is available, appropriate working must be shown. The structured graphs contain information required to solve the questions.
Question 1
7 marksQuestion 2
7 marksQuestion 3
11 marksQuestion 4
12 marksQuestion 5
11 marksQuestion 6
12 marksWorked Solutions And Marking Guide
Section A Question 1
Answer: 16
1+i=sqrt2,mathrm(cis)(pi / 4), so the eighth power is 16,mathrm(cis)(2pi)=16.
Section A Question 2
Answer: costheta=frac49
The normals are (1,2,2) and (2,-1,2). Their dot product is 4 and each has magnitude 3.
Section A Question 3
Answer: 1
((dy) / (dx))=((e^t(1+t)) / (e^t))=1+t, which equals 1 at t=0.
Section A Question 4
Answer: y=3+2e^(-x)
The equilibrium is 3, so y=3+Ce^(-x). The initial condition gives C=2.
Section A Question 5
Answer: 6
The velocity is -6sin(2t)mathbf i+6cos(2t)mathbf j, whose magnitude is 6.
Section A Question 6
Answer: 3.92
The standard error is 12 / √36=2, so the margin of error is 1.96(2)=3.92.
Section A Question 7
Answer: y=-x
Let z=x+iy. Equating squared distances gives (x-2)²+y²=x²+(y+2)², which simplifies to y=-x.
Section A Question 8
Answer: 8
By De Moivre's theorem, z³=8,mathrm(cis)(2pi)=8.
Section A Question 9
Answer: frac23
The distance is ((|2(1)-2+2(3)-4|) / (√(2²+(-1)²+2²)))=frac23.
Section A Question 10
Answer: 3
((dy) / (dx))=((3t²) / (2t))=((3t) / (2)), which equals 3 at t=2.
Section A Question 11
Answer: 0
Using e^x=1+x+x² / 2+ × s and cos x=1-x² / 2+ × s, the two x² / 2 contributions cancel.
Section A Question 12
Answer: frac52
Substitute y=5: 5(1-5 / 10)=5 / 2.
Section A Question 13
Answer: 18 mathrm(N,s)
Impulse is int_0³ 4t,dt=2t^2big|_0³=18 mathrm(N,s).
Section A Question 14
Answer: 20 mathrm(m,s⁻²)
Centripetal acceleration has magnitude v² / r=100 / 5=20 mathrm(m,s⁻²).
Section A Question 15
Answer: t=frac32
The squared separation is (2t-4)²+(2t-2)²=8t²-24t+20, whose vertex occurs at t=24 / 16=3 / 2.
Section A Question 16
Answer: 30 and √21
For a binomial variable, E(X)=np=30 and operatorname(sd)(X)=√(np(1-p))=√21.
Section A Question 17
Answer: frac23
E(X)=int_0¹ x(2x),dx=2 / 3.
Section A Question 18
Answer: 2
The standard deviation of the sample mean is sigma / sqrt n=6 / 3=2.
Section A Question 19
Answer: -1
((dz) / (dt))=ie^(it). At t=pi / 2, this is i(i)=-1.
Section A Question 20
Answer: 2.5
The two Euler steps give y(0.5)=1+0.5(1)=1.5, then y(1)=1.5+0.5(0.5+1.5)=2.5.
Section B Question 1
(a) -5 mathrm(m,s⁻²).
The gradient is ((-20-20) / (8-0))=-5.
(b) 40 mathrm m.
The upward displacement is the triangular area from t=0 to t=4: frac12(4)(20)=40.
(c) The signed areas from 0 to 4 and from 4 to 8 are +40 and -40 square units, so the net displacement at t=8 is zero.
Displacement is signed area under a velocity-time graph. Equal areas above and below the time axis cancel.
(d) 80 mathrm m.
Distance uses absolute area, so 40+40=80.
Mark allocation
- Award 1 mark for the signed gradient with units.
- Award 1 mark for identifying area as displacement and 1 mark for the 40 m height.
- Award 1 mark for comparing the signed areas and 1 mark for the zero-displacement conclusion.
- Award 1 mark for using absolute areas and 1 mark for 80 m.
Section B Question 2
(a) frac12(4)(0.5)=1.
The density graph is a triangle with base 4 and height 0.5.
(b) frac18.
On 0leq xleq2, f(x)=x / 4. Hence Pr(Xleq1)=int_0¹ x / 4,dx=1 / 8.
(c) E(X)=2, by symmetry about x=2.
The triangular density is symmetric about x=2.
(d) E(X²)=((14) / (3)), so operatorname(Var)(X)=E(X²)-[E(X)]²=((14) / (3))-4=frac23.
Use f(x)=x / 4 on [0,2] and f(x)=(4-x) / 4 on [2,4]. Then E(X²)=int_0² x³ / 4,dx+int_2⁴ x²(4-x) / 4,dx=14 / 3.
Mark allocation
- Award 1 mark for the correctly evaluated triangular area.
- Award 1 mark for the left-branch density or equivalent triangle reasoning and 1 mark for the probability.
- Award 1 mark for the mean with a valid symmetry reason.
- Award 1 mark for a correct piecewise second-moment setup, 1 mark for E(X²) = 14 / 3, and 1 mark for the variance.
Section B Question 3
(a) -2, 1+isqrt3, 1-isqrt3.
Write -8=8,mathrm(cis)(pi+2kpi). The cube roots have modulus 2 and arguments pi / 3, pi, 5pi / 3, giving the stated Cartesian forms.
(b) Each side has length 2sqrt3, so the area is 3sqrt3 square units.
The distance between 1+isqrt3 and 1-isqrt3 is 2sqrt3, and each distance to -2 is also √(3²+(sqrt3)²)=2sqrt3. The equilateral-triangle area is ((sqrt3) / (4))(2sqrt3)²=3sqrt3.
(c) w³-3w²+3w+7.
Since z=w-1 and z³+8=0, substitute to obtain (w-1)³+8=w³-3w²+3w+7=0.
Mark allocation
- Award 1 mark for the cube-root modulus and arguments, then up to 3 marks for the complete exact root set.
- Award 2 marks for verifying all equal side lengths and 1 mark for the exact area.
- Award 1 mark for the substitution, 2 marks for correct expansion and 1 mark for the monic polynomial.
Section B Question 4
(a) y=4-3e^(-x² / 2).
Separate variables to obtain int((1) / (4-y)),dy=int x,dx. Hence -ln(4-y)=x² / 2+C. Applying y(0)=1 gives 4-y=3e^(-x² / 2).
(b) The limit is 4, so y=4 is a horizontal asymptote approached from below.
The exponential factor tends to zero as x increases.
(c) The maximum occurs at x=1, and the maximum rate is 3e^(-1 / 2).
From the solution, y'=3xe^(-x² / 2). Differentiating gives y''=3e^(-x² / 2)(1-x²), so the positive rate is maximised at x=1.
(d) y=1.
The point is (0,1) and y'(0)=0, so the tangent is horizontal.
Mark allocation
- Award 2 marks for separation and integration and 2 marks for applying the initial condition correctly.
- Award 1 mark for the limit and 1 mark for the asymptote interpretation.
- Award 2 marks for the rate and its derivative, 1 mark for x=1, and 1 mark for the exact maximum rate.
- Award 1 mark for the tangent gradient and 1 mark for its equation.
Section B Question 5
(a) v(t)=3t²-12t+9=3(t-1)(t-3).
Integrate acceleration and use v(0)=9 to determine the constant.
(b) t=1 and t=3.
Solve 3(t-1)(t-3)=0.
(c) x(t)=t³-6t²+9t.
Integrate velocity and use x(0)=0.
(d) 12 mathrm m.
The direction changes at t=1 and t=3. Since x(0)=0, x(1)=4, x(3)=0 and x(4)=4, the distance is 4+4+4=12.
(e) The maximum speed is 9 mathrm(m,s⁻¹), occurring at t=0 and t=4.
Check the endpoints and the velocity turning point t=2: the velocities are 9,-3,9, so the largest magnitude is 9.
Mark allocation
- Award 1 mark for integration and 1 mark for the velocity constant and factorisation.
- Award 1 mark for solving the rest condition and 1 mark for both times.
- Award 1 mark for integration and 1 mark for the position constant.
- Award 1 mark for splitting at both direction changes, 1 mark for the positions, and 1 mark for the total distance.
- Award 1 mark for checking the velocity turning point and endpoints and 1 mark for the maximum speed with times.
Section B Question 6
(a) k=frac34.
Set kint_0^2x(2-x),dx=1. The integral is 4 / 3, so k=3 / 4.
(b) F(x)=((3x²) / (4))-((x³) / (4)).
Integrate the density from 0 to x: frac34int_0^x(2u-u²),du=frac34(x²-x³ / 3).
(c) frac5(32).
F(3 / 2)=27 / 32, so the upper-tail probability is 1-27 / 32=5 / 32.
(d) E(X)=1 and operatorname(Var)(X)=frac15.
The density is symmetric about 1, so E(X)=1. Also E(X²)=frac34int_0^2x³(2-x),dx=6 / 5, hence the variance is 6 / 5-1=1 / 5.
(e) Approximately 0.132.
The sample mean has mean 1 and standard deviation √((1 / 5) / 25)=1 / (5sqrt5). Thus z=(1.1-1) / (1 / (5sqrt5))approx1.118, giving an upper-tail probability of about 0.132.
Mark allocation
- Award 1 mark for the normalising integral and 1 mark for k.
- Award 2 marks for a correct integral and 1 mark for the simplified CDF.
- Award 1 mark for evaluating the CDF and 1 mark for the upper tail.
- Award 1 mark for the mean, 1 mark for the second moment and 1 mark for the variance.
- Award 1 mark for the sample-mean standard deviation and z-score and 1 mark for the approximate probability.
Diagnostic Checklist
| Topic | Questions | Marks | Marks Lost | Action |
|---|---|---|---|---|
| Multiple-choice foundations | Section A Q1-Q20 | 20 | ___ | Review any missed algebra, complex-number, vector, calculus, mechanics and probability foundations. |
| Mechanics | Section B Q1 and Q5 | 18 | ___ | Review signed area, acceleration, velocity sign changes and total distance. |
| Probability and statistics | Section B Q2 and Q6 | 19 | ___ | Review continuous densities, moments, symmetry and sampling distributions. |
| Complex numbers and geometry | Section B Q3 | 11 | ___ | Review roots in polar form, Argand geometry and transformations of roots. |
| Calculus and differential equations | Section B Q4 | 12 | ___ | Review separation of variables, limiting behaviour, stationary rates and tangents. |