1. Find dy/dx when y = 4/(3x − 1)2.
- A−24/(3x − 1)3
- B−8/(3x − 1)3
- C24/(3x − 1)3
- D−24/(3x − 1)2
Show answer
Answer: A. y = 4(3x − 1)−2, so dy/dx = 4 × (−2)(3x − 1)−3 × 3 = −24/(3x − 1)3. Both the −2 and the chain-rule factor 3 are needed.
Free tests
Video courses
Study notes
Account
Practise AS Level Mathematics (9709) with 167 exam-style MCQs, each with the answer and a short explanation. Every test is marked the moment you finish and shows your score chapter by chapter, so you know what to revise next. It is free and needs no sign-up.
Loading the test…
Practise AS Level Mathematics (9709) with 167 exam-style MCQs, each with the answer and a short explanation. Every test is marked the moment you finish and shows your score chapter by chapter, so you know what to revise next. It is free and needs no sign-up.
167 questions · 3 chapters
The questions follow the syllabus chapter by chapter. You can test the whole subject or one chapter at a time.
12 questions from the test, one or two from each chapter. Try each one, then open the answer.
Answer: A. y = 4(3x − 1)−2, so dy/dx = 4 × (−2)(3x − 1)−3 × 3 = −24/(3x − 1)3. Both the −2 and the chain-rule factor 3 are needed.
Answer: C. Whole system: 30 − 20 = 5a, so a = 2 m s−2. For the 2 kg mass: T − 20 = 2 × 2, so T = 24 N. The tension lies between the two weights.
Answer: C. Fix the last digit first: 3 choices (2, 4 or 6). The remaining three places can be filled in 6 × 5 × 4 = 120 ways. Total 3 × 120 = 360.
Answer: C. No real roots needs b2 − 4ac < 0: 16 − 4k2 < 0, so k2 > 4, giving k < −2 or k > 2. Sketch y = k2 − 4 to get the outside region, not the inside.
Answer: B. Whole system: 3600 − 600 = 1500a, so a = 2 m s−2. Trailer alone: T − 300 = 300 × 2, so T = 900 N. Forgetting the trailer resistance gives 600 N.
Answer: D. Total of A = 200, total of B = 450. Combined mean = 650/25 = 26. Averaging the two means (25) ignores the different group sizes.
Answer: C. The radius from (1, 2) to (4, 6) has gradient 4/3, so the tangent (perpendicular to the radius) has gradient −3/4. y − 6 = −3/4 (x − 4) gives 4y − 24 = −3x + 12, i.e. 3x + 4y = 36.
Answer: A. Along the plane: F = 50 sin 30° = 25 N. Perpendicular: R = 50 cos 30° = 43.3 N. Limiting, so μ = F/R = 25/43.3 = 0.577 (= tan 30°). Using R = 50 N gives the wrong 0.5.
Answer: B. There are 3 vowels (O, A, E). The first and last letters can be chosen in 3 × 2 = 6 ways and the other 5 letters arranged in 5! = 120 ways: 6 × 120 = 720. Using C(3, 2) = 3 for the ends ignores their order and gives 360.
Answer: D. Use sin2θ + cos2θ = 1: the numerator is sin2θ. Then sin2θ/(sin θ cos θ) = sin θ/cos θ = tan θ.
Answer: B. v = u + at: 20 = 5 + 6a, so a = 15/6 = 2.5 m s−2. Use the change in velocity, not the final velocity.
Answer: B. Mean = 12. Variance = Σx2/n − mean2 = 169 − 144 = 25, so the standard deviation is √25 = 5. Do not forget to take the square root.
When you get a question wrong, a short note called "The idea behind this" explains the topic it belongs to, with the rules to remember and a worked example.
Yes. Every test and every explanation is free, and you do not need an account. If you sign in, your results are kept across your devices.
The 167 MCQs are our own, written to the syllabus in the style of the exam.
Instantly. You get your score, the right answer and an explanation for every question, and a list of the topics to work on.
Physics ASPhysics A2Chemistry ASChemistry A2Maths Pure 3Biology ASBiology A2Economics ASEconomics A2Accounting ASAccounting A2Business ASBusiness A2Computer Science ASComputer Science A2Further MathsPsychology ASPsychology A2History