Cambridge A Level Mathematics (US) 9280 — 2014 May/June Paper 3 · Variant 1

*6642769452* Cambridge International Examinations Cambridge International Advanced Level MATHEMATICS (US) 9280/31 Paper 3 Pure Mathematics 3 (P3) May/June 2014 1 hour 45 minutes Additional Materials: Answer Booklet/Paper Graph Paper List of Formulas (MF9) (US) READ THESE INSTRUCTIONS FIRST If you have been given an Answer Booklet, follow the instructions on the front cover of the Booklet. Write your Center number, candidate number, and name on the work you hand in. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue, or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all the questions. Give non-exact numerical answers correct to 3 significant figures, or 1 decimal place in the case of angles in degrees, unless a different level of accuracy is specified in the question. The use of an electronic calculator is expected, where appropriate. You are reminded of the need for clear presentation in your answers. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. The total number of marks for this paper is 75. Questions carrying smaller numbers of marks are printed earlier in the paper, and questions carrying larger numbers of marks later in the paper. This document consists of 3 printed pages and 1 blank page. JC14 06_9280_31/FP © UCLES 2014 [Turn over

2 1 (i) Simplify sin 2! sec !. [2] (ii) Given that 3 cos 2" + 7 cos " = 0, find the exact value of cos ". [3] 2 Use the substitution u = 1 + 3 tan x to find the exact value of Ô 1 40 0 1 + 3 tan x cos2x dx. 5 3 The parametric equations of a curve are x = ln2t + 3, y = 3t + 2 2t + 3. Find the slope of the curve at the point where it crosses the y-axis. [6] 4 The variables x and y are related by the differential equation dy dx = 6ye3x 2 + e3x . Given that y = 36 when x = 0, find an expression for y in terms of x. [6] 5 The complex number Ï is defined by Ï = 9ï3 + 9i ï3 −i . Find, showing all your working, (i) an expression for Ï in the form rei1, where r > 0 and −0 < 1 ≤0, [5] (ii) the two square roots of Ï, giving your answers in the form rei1, where r > 0 and −0 < 1 ≤0. [3] 6 It is given that 2 ln4x −5 + lnx + 1 = 3 ln 3. (i) Show that 16x3 −24x2 −15x −2 = 0. [3] (ii) By first using the factor theorem, factorize 16x3 −24x2 −15x −2 completely. [4] (iii) Hence solve the equation 2 ln4x −5 + lnx + 1 = 3 ln 3. [1] 7 The straight line l has equation r = 4i −j + 2k + ,2i −3j + 6k. The plane p passes through the point 4, −1, 2 and is perpendicular to l. (i) Find the equation of p, giving your answer in the form ax + by + cÏ = d. [2] (ii) Find the perpendicular distance from the origin to p. [3] (iii) A second plane q is parallel to p and the perpendicular distance between p and q is 14 units. Find the possible equations of q. [3] © UCLES 2014 9280/31/M/J/14

3 8 (i) By sketching each of the graphs y = cosecx and y = x0 −x for 0 < x < 0, show that the equation cosecx = x0 −x has exactly two real roots in the interval 0 < x < 0. [3] (ii) Show that the equation cosecx = x0 −x can be written in the form x = 1 + x2 sin x 0 sin x . [2] (iii) The two real roots of the equation cosec x = x0 −x in the interval 0 < x < 0 are denoted by ! and ", where ! < ". (a) Use the iterative formula xn+1 = 1 + x2 n sin xn 0 sin xn to find ! correct to 2 decimal places. Give the result of each iteration to 4 decimal places. [3] (b) Deduce the value of " correct to 2 decimal places. [1] 9 (i) Express 4 + 12x + x2 3 −x1 + 2x2 in partial fractions. [5] (ii) Hence obtain the expansion of 4 + 12x + x2 3 −x1 + 2x2 in ascending powers of x, up to and including the term in x2. [5] 10 x y O T1 T2 T3 T4 The diagram shows the curve y = 10e−1 2x sin 4x for x ≥0. The stationary points are labeled T1, T2, T3, … as shown. (i) Find the x-coordinates of T1 and T2, giving each x-coordinate correct to 3 decimal places. [6] (ii) It is given that the x-coordinate of Tn is greater than 25. Find the least possible value of n. [4] © UCLES 2014 9280/31/M/J/14

4 BLANK PAGE Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. © UCLES 2014 9280/31/M/J/14