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PhysicsAndMathsTutor.comPaper Reference(s)6663/01Edexcel GCECore Mathematics C1Advanced SubsidiaryQuadraticsCalculators may NOT be used for these questions.Information for CandidatesA booklet ‘Mathematical Formulae and Statistical Tables’ might be needed for some questions.The marks for the parts of questions are shown in round brackets, e.g. (2).There are 16 questions in this test.Advice to CandidatesYou must ensure that your answers to parts of questions are clearly labelled.You must show sufficient working to make your methods clear.Answers without working may not gain full credit.1

PhysicsAndMathsTutor.comC1 Algebra – Quadratics1.(a)Show that x2 6x 11 can be written as(x p)2 qwhere p and q are integers to be found.(2)(b)In the space at the top of page 7, sketch the curve with equation y x2 6x 11,showing clearly any intersections with the coordinate axes.(2)(c)Find the value of the discriminant of x2 6x 11(2)(Total 6 marks)C1 Algebra: Quadratics – Questions2

PhysicsAndMathsTutor.comC1 Algebra – Quadratics2.(a)On the axes below sketch the graphs of(i)y x (4 – x)(ii)y x2 (7 – x)showing clearly the coordinates of the points where the curves cross the coordinateaxes.(5)(b) Show that the x-coordinates of the points of intersection ofy x (4 – x) and y x2 (7 – x)are given by the solutions to the equation x(x2 – 8x 4) 0(3)The point A lies on both of the curves and the x and y coordinates of A are both positive.(c)Find the exact coordinates of A, leaving your answer in the form (p q 3, r s 3),where p, q, r and s are integers.(7)(Total 15 marks)C1 Algebra: Quadratics – Questions3

C1 Algebra – QuadraticsPhysicsAndMathsTutor.comf(x) x2 4kx (3 11k), where k is a constant.3.(a)Express f(x) in the form (x p)2 q, where p and q are constants to be found in termsof k.(3)Given that the equation f(x) 0 has no real roots,(b)find the set of possible values of k.(4)Given that k 1,(c)sketch the graph of y f(x), showing the coordinates of any point at which the graphcrosses a coordinate axis.(3)(Total 10 marks)4.The equation x2 3px p 0, where p is a non-zero constant, has equal roots.Find the value of p.(Total 4 marks)C1 Algebra: Quadratics – Questions4

PhysicsAndMathsTutor.comC1 Algebra – Quadratics5.(a)Factorise completely x3 – 6x2 9x(3)(b)Sketch the curve with equationy x3 – 6x2 9xshowing the coordinates of the points at which the curve meets the x-axis.(4)Using your answer to part (b), or otherwise,(c)sketch, on a separate diagram, the curve with equationy (x – 2)3 – 6(x – 2)2 9(x – 2)showing the coordinates of the points at which the curve meets the x-axis.(2)(Total 9 marks)6.The equation kx 2 4 x (5 k ) 0 , where k is a constant, has 2 different real solutions for x.(a)Show that k satisfiesk 2 5k 4 0.(3)(b)Hence find the set of possible values of k.(4)(Total 7 marks)C1 Algebra: Quadratics – Questions5

PhysicsAndMathsTutor.comC1 Algebra – Quadratics7.Given that the equation 2qx2 qx – 1 0, where q is a constant, has no real roots,(a)show that q2 8q 0.(2)(b)Hence find the set of possible values of q.(3)(Total 5 marks)8.The equationx2 kx 8 khas no real solutions for x.(a)Show that k satisfies k2 4k – 32 0.(3)(b)Hence find the set of possible values of k.(4)(Total 7 marks)9.Find the set of values of x for whichx 2 – 7x – 18 0.(Total 4 marks)10.The equation x2 2px (3p 4) 0, where p is a positive constant, has equal roots.(a)Find the value of p.(4)(b)For this value of p, solve the equation x2 2px (3p 4) 0.(2)(Total 6 marks)C1 Algebra: Quadratics – Questions6

C1 Algebra – QuadraticsPhysicsAndMathsTutor.com11.x2 2x 3 (x a)2 b.(a)Find the values of the constants a and b.(2)(b)In the space provided below, sketch the graph of y x2 2x 3, indicating clearly thecoordinates of any intersections with the coordinate axes.(3)(c)Find the value of the discriminant of x2 2x 3. Explain how the sign of thediscriminant relates to your sketch in part (b).(2)The equation x2 kx 3 0, where k is a constant, has no real roots.(d)Find the set of possible values of k, giving your answer in surd form.(4)(Total 11 marks)C1 Algebra: Quadratics – Questions7

PhysicsAndMathsTutor.comC1 Algebra – Quadratics12.yCAPROQxThe diagram above shows part of the curve C with equation y x2 – 6x 18. The curve meetsthe y-axis at the point A and has a minimum at the point P.(a)Express x2 – 6x 18 in the form (x – a)2 b, where a and b are integers.(3)(b)Find the coordinates of P.(2)(c)Find an equation of the tangent to C at A.(4)The tangent to C at A meets the x-axis at the point Q.(d)Verify that PQ is parallel to the y-axis.(1)The shaded region R in the diagram is enclosed by C, the tangent at A and the line PQ.(e)Use calculus to find the area of R.(5)(Total 15 marks)C1 Algebra: Quadratics – Questions8

C1 Algebra – Quadratics13.PhysicsAndMathsTutor.comGiven that the equation kx2 12x k 0, where k is a positive constant, has equal roots, findthe value of k.(Total 4 marks)14.Given that f(x) x2 – 6x 18, x 0,(a)express f(x) in the form (x – a)2 b, where a and b are integers.(3)The curve C with equation y f(x), x 0, meets the y-axis at P and has a minimum point at Q.(b)Sketch the graph of C, showing the coordinates of P and Q.(4)The line y 41 meets C at the point R.(c)Find the x-coordinate of R, giving your answer in the form p q 2, where p and q areintegers.(5)(Total 12 marks)15.f(x) x2 – kx 9, where k is a constant.(a)Find the set of values of k for which the equation f(x) 0 has no real solutions.(4)Given that k 4,(b)express f(x) in the form (x – p)2 q, where p and q are constants to be found,(3)(c)write down the minimum value of f(x) and the value of x for which this occurs.(2)(Total 9 marks)C1 Algebra: Quadratics – Questions9

C1 Algebra – Quadratics16.(a)PhysicsAndMathsTutor.comSolve the equation 4x2 12x 0.(3)f(x) 4x2 12x c, where c is a constant.(b)Given that f(x) 0 has equal roots, find the value of c and hence solve f(x) 0.(4)(Total 7 marks)C1 Algebra: Quadratics – Questions10

PhysicsAndMathsTutor.comC1 Algebra – Quadratics1.(a)( x 3)2 2or p 3 or62q 2B1B12NoteIgnore an “ 0” so (x 3)2 2 0 can score both marks(b)U shape with min in 2nd quad(Must be above x-axis and not on y axis)B1U shape crossing y-axis at (0, 11) only(Condone (11,0) marked on y-axis)B12NoteThe U shape can be interpreted fairly generously. Penalise anobvious V on 1st B1 only.The U needn’t have equal “arms” as long as there is a clear minthat “holds water”st1 B1 for U shape with minimum in 2nd quad. Curve need not crossthe y-axis but minimum should NOT touch x-axis and shouldbe left of (not on) y-axis2nd B1for U shaped curve crossing at (0, 11). Just 11 marked on y-axisis fine. The point must be marked on the sketch (do not allowfrom a table of values) Condone stopping at (0, 11)(c)b 2 4ac 62 4 11M1 8A1C1 Algebra: Quadratics – Mark Schemes211

C1 Algebra – QuadraticsPhysicsAndMathsTutor.comNoteM1A1for some correct substitution into b2 – 4ac. This may be as partof the quadratic formula but must be in part (c) and must beonly numbers (no x terms present).Substitution into b2 4ac or b2 4ac or b2 4ac is M0for – 8 only.If they write – 8 0 treat the 0 as ISW and award A1If they write – 8 0 then score A0A substitution in the quadratic formula leading to – 8 insidethe square root is A0.So substituting into b2 – 4ac 0 leading to – 8 0 can score M1A1.Only award marks for use of the discriminant in part (c)[6]2.(a)(i)(ii) shape (anywhere on diagram)B1Passing through or stopping at (0, 0) and (4, 0)only(Needn’t be shape)B1correct shape (-ve cubic) with a max and min drawn anywhereB1Minimum or maximum at (0, 0)B1Passes through or stops at (7, 0) but NOT touching.B1(7, 0) should be to right of (4, 0) or B0Condone (0, 4) or (0, 7) marked correctly on x-axis.Don’t penalise poor overlap near origin.Points must be marked on the sketch.not in the textC1 Algebra: Quadratics – Mark Schemes512

PhysicsAndMathsTutor.comC1 Algebra – Quadratics(b)x (4 x ) x 2 ( 7 x ) (0 ) x[7 x x 2 (4 x)](0 ) x[7 x x 2 (4 x)](M1(o.e.)B1ft)0 x x 2 8 x 4 *A1 cso3NoteM1B1for forming a suitable equationfor a common factor of x taken out legitimately. Can treat thisas an M mark. Can ft their cubic 0 found from an attempt atsolving their equations e.g. x3 – 8x2 – 4x x(.A1cso no incorrect working seen. The “ 0” is required but condonemissing from some lines of working. Cancelling the x scores B0A0.(c)(8 64 160 x 8x 4 x 22)0)( x 4 ) 42 4( or212( x 4) 2M1A1 8 4 32or 2( x 4) B13x 4 2 3A1From sketch A is x 4 2 3M1So()(y 4 2 3 4 [4 2 3])(dependent on 1st M1) M1 12 8 3A17Note1st M1 for some use of the correct formula or attempt to completethe squarest1 A1 for a fully correct expression: condone instead of B1or for (x – 4)2 12for simplifying 48 4 3 or 12 2 3 .Can be scoredindependently of this expression2nd A1 for correct solution of the form p q 3 : can be or or –2nd M1 for selecting their answer in the interval (0, 4). If they have novalue in (0, 4) score M03rd M1 for attempting y using their x in correct equation. Anexpression needed for M1A03rd A1 for correct answer. If 2 answers are given A0.[15]C1 Algebra: Quadratics – Mark Schemes13

PhysicsAndMathsTutor.comC1 Algebra – Quadratics3.(a)(x 2k)2 or x 4k 2 2M1(x F)2 G 3 11k (where F and G are any functions of k,not involving x)M1(x 2k)2 – 4k2 (3 11k) Accept unsimplifiedequivalents such asA12and i.s.w. if necessary.(b)324k 4k x – 3 11k ,2 2 Accept part (b) solutions seen in part (a).“4k 2 –11k – 3” 0(4k 1)(k – 3) 0k ,M1[Or, ‘starting again’, b2 – 4ac (4k)2 – 4(3 11k)and proceed to k ] –1 k 3 (Ignore any inequalities4for the first 2 marks in (b)).A1Using b2 – 4ac 0 for no real roots, i.e. “4k2 –11k – 3” 0,to establish inequalities involving their twocritical values m and nM1(even if the inequalities are wrong, e.g. k m, k n).–1 k 3 (See conditions below) Follow through4their critical values.A1ft4The final A1ft is still scored if the answer m k nfollows k m, k n.Using x instead of k in the final answer loses only the 2ndA mark, (condone use of x in earlier working).C1 Algebra: Quadratics – Mark Schemes14

PhysicsAndMathsTutor.comC1 Algebra – QuadraticsNote1st M: Forming and solving a 3-term quadratic in k (usual rules.see general principles at end of scheme). The quadratic mustcome from “b2 – 4ac”, or from the “q” in part (a).Using wrong discriminant, e.g. “b2 4ac” will scoreno marks in part (b).2nd M: As defined in main scheme above.2nd A1ft: m k n, where m n, for their critical values m and n.Other possible forms of the answer(in each case m n):(i) n k m(ii) k m and k nIn this case the word “and” must be seen(implying intersection).(iii) k (m,n)(iv) {k :k m} {k :k n}Not just a number line.Not just k m, k n (without the word “and”).(c)Shape(seen in (c))Minimum in correct quadrant, not touching the x-axis, not on they-axis, and there must be no other minimum or maximum.B1B1(0, 14) or 14 on y-axis.Allow (14, 0) marked on y-axis.n.b. Minimum is at (–2,10), (but there is no mark for this).B13NoteFinal B1 is dependent upon a sketch having been attemptedin part (c).[10]C1 Algebra: Quadratics – Mark Schemes15

PhysicsAndMathsTutor.comC1 Algebra – Quadratics4.b2 – 4ac attempted, in terms of p.(3p)2 – 4p 0 o.e.M1Attempt to solve for p e.g. P(9p – 4) 0 Must potentially lead top k, k 0p 49(Ignore p 0, if seen)A1M1A1csoNote1st M1 for an attempt to substitute into b2 – 4ac or b2 4ac with b or c correctCondone x’s in one term only.This can be inside a square root as part of the quadratic formula forexample.Use of inequalities can score the M marks only1st A1 for any correct equation: (3p)2 – 4 1 p 0 or better2nd M1 for an attempt to factorize or solve their quadratic expression in p.49Method must be sufficient to lead to their p .Accept factors or use of quadratic formula or ( p 92 ) k 2 (o.e. eg) (3 p 23 ) k2 or equivalent work on their eqn.22which would lead to 9p 4 is OK for this 2nd M1ALTComparing coefficientsM1for (x α)2 x2 α2 2αx and A1 for a correct equation eg 3p 2 PM1for forming solving leading to P 23 or betterUse of quadratic/discriminant formula (or any formula) Rule for awarding M markIf the formula is quoted accept some correct substitution leading to apartially correct expression.If the formula is not quoted only award for a fully correct expression usingtheir values.[4]C1 Algebra: Quadratics – Mark Schemes16

C1 Algebra – Quadratics5.(a)PhysicsAndMathsTutor.comx(x2 – 6x 9) x(x – 3)(x – 3)B1M1 A13NoteB1 for correctly taking out a factor of xM1 for an attempt to factorize their 3TQ e.g. (x p)(x q)where pq 9.So (x – 3)(x 3) will score M1 but A0A1 for a fully correct factorized expression – accept x(x – 3)2If they “solve” use ISWS.C.If the only correct linear factor is (x – 3), perhaps from factortheorem, award B0M1A0Do not award marks for factorising in part (b)For the graphs“Sharp points” will lose the 1st B1 in (b) but otherwise begenerous on shape Condone (0, 3) in (b) and (0, 2), (0,5) in (c) ifthe points are marked in the correct places.(b)ShapeThrough origin (not touching)Touching x-axis only onceTouching at (3, 0), or 3 on x-axis[Must be on graph not in a table]B1B1B1ft4Note2nd B1 for a curve that starts or terminates at (0, 0) score B04th B1ft for a curve that touches (not crossing or terminating) at (a, 0)where their y x(x – a)2C1 Algebra: Quadratics – Mark Schemes17

C1 Algebra – QuadraticsPhysicsAndMathsTutor.com(c)Moved horizontally (either way)(2, 0) and (5, 0), or 2 and 5 on x-axisM1A12NoteM1 for their graph moved horizontally (only) or a fully correct graphCondone a partial stretch if ignoring their values looks like a simpletranslationA1 for their graph translated 2 to the right and crossing or touchingthe axis at 2 and 5 onlyAllow a fully correct graph (as shown above) to score M1A1whatever they have in (b)[9]6.(a)b2 – 4ac 0 16 – 4k(5 – k) 0 or equiv., e.g. 16 4k(5 – k) M1A1So k2 – 5k 4 0 (Allow any order of terms,e.g. 4 – 5k k2 0)(*) A1cso3NoteM1for attempting to use the discriminant of the initial equation( 0 not required, but substitution of a, b and c in the correctformula is required).If the formula b2 – 4ac is seen, at least 2 of a, b and c must becorrect.If the formula b2 – 4ac is not seen, all 3 (a, b and c) mustbe correct.This mark can still be scored if substitution in b2 – 4ac is withinthe quadratic formula.This mark can also be scored by comparing b2 and 4ac (withsubstitution).However, use of b2 4ac is M0.1st A1 for fully correct expression, possibly unsimplified, with symbol. NB must appear before the last line, even if this issimply in a statement such as b2 – 4ac 0 or ‘discriminantpositive’.Condone a bracketing slip, e.g. 16 – 4 k 5 – k if subsequentwork is correct and convincing.C1 Algebra: Quadratics – Mark Schemes18

PhysicsAndMathsTutor.comC1 Algebra – Quadratics2nd A1 for a fully correct derivation with no incorrect working seen.Condone a bracketing slip if otherwise correct and convincing.Using b 2 – 4ac 0 :Only available mark is the first M1 (unless recovery is seen).(b)Critical Values(k – 4)(k – 1) 0k .k 1 or 4M1A1Choosing “outside” region M1k 1 or k 4A14Note1st M1 for attempt to solve an appropriate 3TQ1st A1 for both k 1 and 4 (only the critical values are required,so accept, e.g. k 1 and k 4). * *2nd M1 for choosing the “outside” region. A diagram or tablealone is not sufficient. Follow through their values of k.The set of values must be ‘narrowed down’ to score thisM mark listing everythingk 1, 1 k 4, k 4 is M02nd A1 for correct answer only, condone “k 1, k 4” andeven “k 1 and k 4”,.but “1 k 4” is A0.* * Often the statement k 1 and k 4 is followed by the correct finalanswer. Allow full marks.Seeing 1 and 4 used as critical values gives the first M1 A1 byimplication.In part (b), condone working with x’s except for the final mark, wherethe set of values must be a set of values of k (i.e. 3 marks out of 4).Use of (or ) in the final answer loses the final mark.[7]C1 Algebra: Quadratics – Mark Schemes19

PhysicsAndMathsTutor.comC1 Algebra – Quadratics7.(a)[No real roots implies b2 – 4ac 0.] b2 – 4ac q2 – 4 2q (–1) M1So q2 – 4 2q (–1) 0 i.e. q2 8q 0 (*)A1csoM12for attempting b2 – 4ac with one of b or a correct. 0 not needed for M1This may be inside a square root.A1cso for simplifying to printed result with no incorrect workingor statements seen.Need an intermediate stepe.g.q2 – –8q 0 or q2 – 4 2q –1 0 or q2 – 4(2q)(–1) 0or q2 –8q(–1) 0 or q2 – 8q –1 0i.e. must have or brackets on the 4ac term 0 must be seen at least one line before the final answer.(b)q(q 8) 0 or (q 4)2 16 0(q) 0 or –8–8 q 0 or q (–8, 0) or q 0 and q –8M1(2 cvs)M1A1A1ft3for factorizing or completing the square or attempting tosolve q2 8q 0. A method that would lead to 2 valuesfor q. The “ 0” may be implied by values appearing later.1st A1 for q 0 and q –82nd A1 for –8 q 0. Can follow through their cvs but mustchoose “inside” region.q 0, q –8 is A0, q 0 or q –8 is A0,(–8, 0) on its own is A0BUT “ q 0 and q –8” is A1Do not accept a number line for final mark[5]C1 Algebra: Quadratics – Mark Schemes20

PhysicsAndMathsTutor.comC1 Algebra – Quadratics8.(a)x2 kx (8 – k) ( 0)b2 – 4ac k2 – 4(8 – k)8 – k need not be bracketedM1M1b2 – 4ac 0 k2 4k – 32 0(*)A1cso31st M: Using the k from the right hand side to form 3-termquadratic in x (‘ 0’ can be implied), or k 2 2attempting to complete the square x k2 8 k ( 0)4or equiv., using the k from the right hand side.For either approach, condone sign errors.1st M may be implied when candidate moves straight to thediscriminant.2nd M: Dependent on the 1st M.Forming expressions in k (with no x’s) by using b2 and 4ac.(Usually seen as the discriminant b2 – 4ac, but separateexpressions are fine, and also allow the use of b2 4ac.(For ‘completing the square’ approach, the expression mustbe clearly separated from the equation in x).If b2 and 4ac are used in the quadratic formula, they mustbe clearly separated from the formula to score this mark.For any approach, condone sign errors.If the wrong statement b 2 4ac 0 is seen, maximum score is M1 M1 A0.(b)(k 8)(k – 4) 0k .k –8k 4Choosing ‘inside’ region (between the two k values)–8 k 4 or 4 k –8M1A1M1A14Condone the use of (instead of k) in part (b).1st M: Attempt to solve a 3-term quadratic equation in k.It might be different from the given quadratic in part (a).Ignore the use of in solving the equation. The 1st M1 A1 can bescored if –8 and 4 are achieved, even if stated as k –8, k 4.Allow the first M1 A1 to be scored in part (a).N.B. ‘k –8, k 4’ scores 2nd M1 A0‘k –8 or k 4’ scores 2nd M1 A0‘k –8 and k 4’ scores 2nd M1 A1‘k –7, – 6, – 5, – 4, – 3, – 2, –1, 0, 1, 2, 3’ scores 2nd M0 A0Use of (in the answer) loses the final mark.[7]C1 Algebra: Quadratics – Mark Schemes21

PhysicsAndMathsTutor.comC1 Algebra – Quadratics9.Critical Values(x a)(x b) with ab 18 or x (x – 9)(x 2)or x Solving Inequality7 1127 49 722orx 9 or x 2x ( x 72 ) 2 ( 72 ) 182orM17 11 22Choosing “outside”A1M1 A11st M1 For attempting to find critical values.Factors alone are OK for M1, x appearing somewhere for the formula and aswritten for completing the square1st A1 Factors alone are OK. Formula or completing the square need x as written.2nd M1 For choosing outside region. Can f.t. their critical values.They must have two different critical values. 2 x 9 i

Paper Reference(s) 6663/01 . Edexcel GCE . Core Mathematics C1 . Advanced Subsidiary . Quadratics . Calculators may NOT be used for these questions. Information for Candidates . A booklet ‘Mathematical Formulae and Statistical Tables’ might be needed for some questions. The marks for the parts of questions are shown in ro

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