A Level Maths Paper 3
Covers Proof and Algebraic Methods, Coordinate Geometry, Sequences, Series and the Binomial Expansion and 11 more.
Questions
Question 1 [2 marks]
Sequences, Series and the Binomial Expansion
An arithmetic sequence has first term 5 and common difference 3.
Find the 20th term.
Question 2 [2 marks]
Coordinate Geometry
Find the equation of the straight line that passes through the points (1, 4) and (5, -8), giving your answer in the form y = mx + c.
Question 3 [3 marks]
Integration
Evaluate the definite integral of (3x^2 - 2x + 1) with respect to x between x = -1 and x = 2.
Question 4 [3 marks]
Vectors
Find the magnitude of the vector v = 5i - 12j, and find a unit vector in the same direction as v.
Question 5 [4 marks]
Differentiation
Using differentiation from first principles, show that the derivative of x^2 is 2x.
Question 6 [4 marks]
Exponentials and Logarithms
Solve the equation 5^(2x - 1) = 30, giving your answer to 3 significant figures.
Question 7 [4 marks]
Proof and Algebraic Methods
Without using a calculator, find the quotient and remainder when 2x^3 - 3x^2 + 4x - 1 is divided by (x - 1).
Question 8 [5 marks]
Forces and Newton's Laws
A block of mass 6 kg lies on a rough horizontal surface. The coefficient of friction between the block and the surface is 0.25. A horizontal force of 20 N is applied to the block.
Find the acceleration of the block. Use g = 9.8 m/s^2.
Question 9 [5 marks]
Moments
A non-uniform plank AB has length 5 m and weight 120 N, and rests horizontally on two supports at A and B. When a block of weight 60 N is placed at a point 2 m from A, the reaction at A is 100 N.
Find the reaction at B in this situation, and find the distance of the centre of mass of the plank from A.
Question 10 [5 marks]
Trigonometry
Express 3 sin(x) + 4 cos(x) in the form R sin(x + alpha), where R > 0 and 0 < alpha < 90 deg, giving the value of alpha to 1 decimal place.
Hence state the maximum value of 3 sin(x) + 4 cos(x), and the smallest positive value of x, in degrees, at which it occurs.
Question 11 [5 marks]
Probability and the Binomial Distribution
Two fair six-sided dice are thrown, and the sum of the two scores is recorded.
Find the probability that the sum is a prime number, given that at least one die shows a 5.
Question 12 [6 marks]
Sampling and Data Presentation
A college has 900 students: 340 study Sciences, 260 study Humanities and 300 study Arts. A stratified sample of 45 students is to be selected by subject, and within Sciences, systematic sampling is then used to choose the required number from a numbered list of all 340 Science students.
Find the number of Science students needed in the sample, and find the sampling interval that should be used for the systematic sampling.
Question 13 [6 marks]
Kinematics
A particle P moves in a straight line such that its displacement s metres from a fixed point O at time t seconds (t >= 0) is given by s = t^3 - 7t^2 + 10t.
Find the two values of t (other than t = 0) at which P is at O, and find the velocity of P at the larger of these two times.
Question 14 [6 marks]
The Normal Distribution and Hypothesis Testing
A seed supplier claims that 40% of a particular type of seed germinate within one week of planting. A gardener believes the true proportion is lower and plants a random sample of 25 of the seeds.
Using the binomial distribution X ~ B(25, 0.4), find the critical region for a test of H0: p = 0.4 against H1: p < 0.4 at the 5% significance level, stating the actual significance level. Given that 6 of the 25 seeds germinate within a week, state the conclusion of the test.
Model solutions
| Question 1[2 marks] | |
|---|---|
| Answer or working | Marks |
| using term = a + (n - 1)d | M1 |
| 62 | A1 |
| Question 2[2 marks] | |
|---|---|
| Answer or working | Marks |
| gradient = (-8 - 4)/(5 - 1) = -3 | M1 |
| y = -3x + 7 | A1 |
| Question 3[3 marks] | |
|---|---|
| Answer or working | Marks |
| the antiderivative x^3 - x^2 + x | M1 |
| substituting the limits x = 2 and x = -1 | M1 |
| the value 9 | A1 |
| Final answer: 9 | |
| Question 4[3 marks] | |
|---|---|
| Answer or working | Marks |
| |v| = sqrt(5^2 + 12^2) | M1 |
| |v| = 13 | A1 |
| the unit vector (5/13)i - (12/13)j | A1 |
| Final answer: |v| = 13; unit vector = (5/13)i - (12/13)j | |
| Question 5[4 marks] | |
|---|---|
| Answer or working | Marks |
| writing f'(x) = lim as h tends to 0 of [(x + h)^2 - x^2]/h | M1 |
| expanding (x + h)^2 = x^2 + 2xh + h^2 | M1 |
| simplifying the difference quotient to 2x + h | A1 |
| taking the limit as h tends to 0 to give f'(x) = 2x, completing the proof | A1 |
| Final answer: Proof: f'(x) = lim (h -> 0) of (2x + h) = 2x | |
| Question 6[4 marks] | |
|---|---|
| Answer or working | Marks |
| taking logarithms of both sides | M1 |
| using the power law to give (2x - 1) ln(5) = ln(30) | M1 |
| 2x - 1 = 2.1133 (or equivalent unrounded value) | A1 |
| x = 1.56 (3 sf) | A1 |
| Question 7[4 marks] | |
|---|---|
| Answer or working | Marks |
| dividing to obtain the first term of the quotient, 2x^2 | M1 |
| continuing the division to find the remaining terms of the quotient | M1 |
| the quotient 2x^2 - x + 3 | A1 |
| the remainder 2 | A1 |
| Final answer: Quotient = 2x^2 - x + 3, remainder = 2 | |
| Question 8[5 marks] | |
|---|---|
| Answer or working | Marks |
| finding the normal reaction R = mg = 58.8 N | M1 |
| finding the friction force = mu x R = 14.7 N | M1 |
| recognising the applied force exceeds the maximum friction, so the resultant force = 20 - 14.7 | M1 |
| resultant force = 5.3 N | A1 |
| a = 0.883 m/s^2 (3 sf) | A1 |
| Question 9[5 marks] | |
|---|---|
| Answer or working | Marks |
| vertical equilibrium to find R_B = 180 - 100 = 80 N | M1 |
| taking moments about A: R_B x 5 = 120x + 60 x 2, using x for the distance of the centre of mass from A | M1 |
| forming the equation 400 = 120x + 120 | A1 |
| solving for x | M1 |
| x = 2.33 m (3 sf) | A1 |
| Final answer: R_B = 80 N; centre of mass is 2.33 m from A (3 sf) | |
| Question 10[5 marks] | |
|---|---|
| Answer or working | Marks |
| using R = sqrt(3^2 + 4^2) | M1 |
| R = 5 | A1 |
| using tan(alpha) = 4/3 | M1 |
| alpha = 53.1 deg (1 dp) | A1 |
| the maximum value 5, occurring at x = 90 - 53.1 = 36.9 deg (1 dp) | A1 |
| Final answer: R = 5, alpha = 53.1 deg; maximum value = 5 at x = 36.9 deg (1 dp) | |
| Question 11[5 marks] | |
|---|---|
| Answer or working | Marks |
| identifying the 11 equally likely outcomes in which at least one die shows a 5 | M1 |
| listing the corresponding sums (6, 7, 8, 9, 10 or 11) | M1 |
| identifying that the sums 7 and 11 are prime | A1 |
| counting 4 outcomes that give a prime sum | A1 |
| the probability = 4/11 | A1 |
| Final answer: 4/11 | |
| Question 12[6 marks] | |
|---|---|
| Answer or working | Marks |
| the sampling fraction = 45/900 = 0.05 | M1 |
| multiplying the Science total by the fraction | M1 |
| the Science sample size = 17 | A1 |
| the systematic sampling interval = population size / sample size | M1 |
| the interval = 340/17 = 20 | A1 |
| a correct statement of how the systematic sample would then be chosen, e.g. select a random start between 1 and 20 and then every 20th student thereafter | B1 |
| Final answer: 17 Science students needed; systematic sampling interval = 20 | |
| Question 13[6 marks] | |
|---|---|
| Answer or working | Marks |
| factorising s = t(t^2 - 7t + 10) | M1 |
| s = t(t - 2)(t - 5), giving t = 2 and t = 5 | A1 |
| differentiating to find v = 3t^2 - 14t + 10 | M1 |
| substituting t = 5 into v | M1 |
| v = 75 - 70 + 10 | A1 |
| v = 15 m/s | A1 |
| Final answer: t = 2 s and t = 5 s; velocity at t = 5 is 15 m/s | |
| Question 14[6 marks] | |
|---|---|
| Answer or working | Marks |
| identifying X ~ B(25, 0.4) and attempting cumulative probabilities under H0 | M1 |
| P(X <= 5) = 0.0294 (accept | A1awrt |
| P(X <= 6) = 0.0736 (accept awrt), confirming this exceeds 0.05 | A1 |
| the critical region X <= 5, with actual significance level 0.0294 (2.94%) | A1 |
| noting that 6 does not lie in the critical region, since 6 > 5 | A1 |
| the conclusion: insufficient evidence at the 5% level that the true proportion germinating is lower than 40% | A1 |
| Final answer: Critical region X <= 5 (significance level 0.0294); since 6 is not in the critical region, there is insufficient evidence that the true proportion is lower than 40% | |