2021 NTSS Prelim 4E AM P2 MS v20210805a

This document consists of 16 printed pages. Setter: Mr Alan Cheng NEW TOWN SECONDARY SCHOOL Preliminary Examination Secondary 4 Express NAME Mark Scheme CLASS INDEX NUMBER Additional Mathematics Paper 2 4049/02 2 August 2021 09:05 – 11:20 2 hours 15 min READ THESE INSTRUCTIONS FIRST Write your name, register number and class in the spaces provided above and on all 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 paper clips, glue or correction fluid. 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 approved scientific calculator is expected, where appropriate. You are reminded of the need for clear presentation in your answers. 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 90. For Examiner’s Use

2 Mathematical Formulae 1. ALGEBRA Quadratic Equation For the equation 02 =++ cbxax , 2( 4 ) 2 b b acx a −  −= . Binomial Expansion nrrnnnnn bbar nbanbanaba ++     ++     +     +=+ −−− 221 21)( , where n is a positive integer and ( ) ! ( 1) ( 1) ! ! ! n n n n n r r r n r r  − − +== − 2. TRIGONOMETRY Identities sin2 A + cos2 A = 1 sec2 A = 1 + tan2 A cosec2 A = 1 + cot2 A BABABA sincoscossin)sin( = BABABA sinsincoscos)cos( = BA BABA tantan1 tantan)tan(  = AAA cossin22sin = AAAAA 2222 sin211cos2sincos2cos −=−=−= A AA 2tan1 tan22tan −= Formulae for ABC A a sin = B b sin = C c sin a2 = b2 + c2 − 2bc cos A  = 2 1 bc sin A

3 1 Express ( )( ) 2 2 2 19 13 xx xx +− −+ as a sum of three partial fractions. [5] ( )( ) ( ) ( ) 2 22 2 19 131 3 3 x x A B C xxx x x +− = + +−+− + + [M1 ( ) ( )( ) ( ) 22 2 19 3 1 3 1x x A x B x x C x+ − = + + − + + − [M1] Sub 1x= , 16 16 A−= 1A=− [A1] Sub 3x=− , 16 4 C− =− 4C = [A1] Sub 0x= , 19 9 3A B C− = − − Sub 1A=− , 4C = , 19 9 3 4 B− =− − − 2B= [A1] ( )( ) ( ) ( ) 2 22 2 19 1 2 4 131 3 3 xx xxx x x +− =− + +−+− + +

4 2 The table below shows experimental values of two variables x and y. x 2 4 6 8 y 8.48 5.99 4.90 4.24 It is known that x and y are connected by the equation nyx k= , where k and n are constants. (a) Plot ln y against ln x , using a scale of 4 cm for 1 unit on both axes, for the given data and draw a straight line graph on the