MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Page No: 1/28 SUMMER – 2013 EXAMINATION MODEL ANSWER Subject: BASIC MATHEMATICS Subject Code: 17104 Important Instructions to examiners: The model answer shall be the complete solution for each and every question on the question paper. Numerical shall be completely solved in a step by step manner along with step marking. All alternative solutions shall be offered by the expert along with self-explanatory comments from the expert. In case of theoretical answers, the expert has to write the most acceptable answer and offer comments regarding marking scheme to the assessors. In should offer the most convincing figures / sketches / circuit diagrams / block diagrams / flow diagrams and offer comments for step marking to the assessors. In case of any missing data, the expert shall offer possible assumptions / options and the ensuing solutions along with comments to the assessors for effective assessment. In case of questions which are out of the scope of curricular requirement, the expert examiner shall solve the question and mention the marking scheme in the model answer. However, the experts are requested to submit their clear cut opinion about the scope of such question in the paper separately to the coordinator. Experts shall cross check the DTP of the final draft of the model answer prepared by them. MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. Summer 2013 Page No: 2/28 Model answers Marks Attempt any ten of the following: 2 k 7 1) (a) Ans. Total Marks 20 Find k, if 3 4 13 0 8 11 33 2 k 7 3 4 13 0 8 11 33 2 4 33 1113 k 3 33 13 8 7 33 32 0 1 22 k 5 7 0 15 5k 0 ½ 15 5k 02 k 3 (b) Ans. ½ 1 3 5 7 Find A if , 2 A 3 2 5 6 3 1 3 5 7 2A 3 2 5 6 3 3 2A 6 5 2A 6 9 5 15 6 7 3 3 6 7 3 9 15 2 2 2A 0 12 1 1 A 0 6 c) Ans. d) Ans. ½ 1 ½ 1 4 Prove that the matrix is non-singular matrix. 6 9 1 4 Consider, 6 9 9 24 15 0 Given matrix is non-singular matrix. 2 2 2 3 4 5 ,B If A and C then show that AB AC 2 2 4 5 2 3 2 2 2 3 AB 2 2 4 5 02 02 2 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. Summer 2013 Model answers 12 16 12 16 2 2 4 5 AC 2 2 2 3 12 16 12 16 AB=AC 1. (e) Ans. Resolve into partial fractions: 2x 3 2x 3 x 2 x 3 x 3 x 1 Page No: 3/28 Marks Total Marks 1 1 02 2x 3 x 2x 3 2 2 Let, 2x 3 A B x 3 x 1 x 3 x 1 ½ 2 x 3 x 1 A x 3 B Put x 1 9 4A 9 A 4 Put x 3 1 4 B 1 B 4 2x 3 9 / 4 1/ 4 1 9 1 x 3 x 1 x 3 x 1 4 x 3 x 1 2x 3 2x 3 x 2 x 3 x 3 x 1 ½ ½ 02 ½ OR 2 Let 2x 3 A B x 3 x 1 x 3 x 1 2 x 3 x 1 A x 3 B 2 x 3 A B x A 3B By equating equal power coefficients A 3B 3 A B 2 By solving above equations: ½ MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. 1. Summer 2013 Page No: 4/28 Model answers Ans. Total Marks ½ 9 4 1 B 4 2x 3 9 / 4 1/ 4 x 3 x 1 x 3 x 1 A (f) Marks ½ ½ 02 Prove that 2sin 2 1 cos 2 1 cos 2 1 cos 1 cos .cos sin .sin 1 1 cos2 sin 2 1 cos2 sin 2 sin 2 sin 2 =2sin 2 (g) Ans. Ans. 02 2 02 Define Allied Angles Allied Angle : Any two angles whose sum or difference is either zero or an integral multiple of (h) ½ ½ 2 are called as allied angle. If 2cos 600.cos100 cos A cos B , then find A and B cos 600.cos100 cos A cos B cos 600 100 cos 600 100 cos A cos B 1 cos 700 cos 500 cos A cos B A 700 and B 500 1 02 OR 2 cos 60 .cos10 cos A cos B 0 0 A B A B .cos 2 2 A B 100 2 2 cos 600.cos100 2 cos 1 A B 600 and 2 A B 1200 ½ A B 200 A 700 (i) and B 500 Evaluate without using calculator ½ tan850 tan400 1+tan850 .tan400 02 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. 1. Ans. Summer 2013 Page No: 5/28 Model answers Marks tan850 tan400 1+tan850 .tan400 tan 850 400 Total Marks 1 ½ tan 450 ½ 1 (j) Ans. 1 Prove that cos 1 x sec1 x 1 Let cos x cos x 1 sec x 1 sec 1 x (k) Ans. 02 ½ 1 ½ 02 1 cos 1 x sec 1 x Find the perpendicular distance between the point (3,4) and the line 3x 4 y 5. Perpendicular distance= = ax1 by1 c a 2 b2 3 3 4 4 5 1 32 42 20 5 =4 units = (l) Ans. 02 Range =Largest value-Smallest value Attempt any four of the following: 16 Solve the following equations by using Cramers rule: x y 2 z 1, 2 x 3 y 4 z 4,3x 2 y 6 z 5 1 Ans. 1 1 3,6,10,1,15,16,21,19,18. =20 (a) 02 Find the range of the following distribution: =21-1 2. 1 Let D 2 1 2 3 4 3 2 6 1 18 8 1 12 12 2 4 9 8 1 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) 2. 1 Dx 4 Summer 2013 Page No: 6/28 1 2 3 4 5 2 6 1 18 8 1 24 20 2 8 15 8 ½ 1 1 2 Dy 2 4 4 3 5 6 1 24 20 1 12 12 2 10 12 16 ½ 1 Dy 2 1 1 3 4 3 2 5 115 8 110 12 1 4 9 8 ½ x ½ Dx 8 1 D 8 Dy 16 y 2 D 8 D 8 z z 1 D 8 (b) Ans. ½ 04 ½ 2 -3 x 1 Find x and y if 1 5 1 0 2 x 3 2 4 3 y 2 x 3 x 5 1 2 5 y x 5 2x 3 2x 3 and x 5 x 5 2 2 x 3 2 4 3 y y x 5 1 2 5 y 2 4 3 y 1 2 5 y , 4 3y 4 3y , 2 5y 2 5y 2 2 04 In above all the cases finding the values of x and y are not possible. it has no solution. (c) 1 3 2 1 0 0 2 1 2 If A 1 2 0 , B 1 2 0 and C 2 2 1 4 0 3 1 0 3 1 2 2 then find the matrix D such that 2A-3B-D=C MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. 2. Ans. Ans. 3 2 1 2 0 3 1 0 3 1 6 4 3 0 4 0 3 6 0 6 3 0 5 2 4 1 2 5 0 0 2 2 0 - 2 0 3 1 0 2 1 0 - 2 2 9 1 2 1 2 2 1 2 2 2 1 2 Total Marks x 2x 3 x x 2 x 2 x 1 1 2 3 2 3 1 If A and B 5 1 0 4 4 3 2 3 1 Consider AB 5 1 0 4 4 Resolve into partial fractions: 1 04 7 ' 6 , then show that AB B ' A ' 4 7 6 4 1 ½ ½ 1 17 19 B ' A' 23 28 AB ' B ' A ' Ans. Marks Given, 2 A 3B D C D 2 A 3B C 6 15 4 14 18 4 AB 7 16 3 16 17 28 AB 19 23 17 19 AB ' 28 23 2 1 3 5 4 B ' A' 3 0 7 6 4 1 4 (e) Page No: 7/28 Model answers 1 D 2 1 4 2 D 2 8 3 D 7 4 (d) Summer 2013 1 x x x2 2 2 Let, x x 2 x 1 A B x 2 x 1 1 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. Summer 2013 Model answers Page No: 8/28 Marks Total Marks x x 1 A x 2 B 2. Put x 2 2 A 3 2 3 Put x 1 1 3B A B 1 3 1 x x 2 x 1 (f) 1 Resolve into partial fractions: 9 Ans. 2 / 3 1/ 3 x 3 x 1 1 9 x 1 x 2 2 A B C x 1 x 2 x 2 2 x 1 x 2 2 9 x 2 A x 2 x 1 B x 1 C 2 04 ½ ½ Put x 1 9 9A ½ A=1 Putx 2 9= 3C C 3 ½ Put x 0 9=4A 2 B C 9=4 1 2 B 3 9 7 2B 2 B 2 B 1 9 x 1 x 2 3. 1 2 1 1 3 x 1 x 2 x 2 2 Attempt any four of the following: (a) Using matrix inversion method, solve the following equations: x y z 3, x 2 y 3z 4, x 4 y 9 z 6 1 04 16 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. 3. Ans. Summer 2013 Model answers Page No: 9/28 Marks 1 1 1 x 3 Let A 1 2 3 , X y and B 4 1 4 9 z 6 1 1 1 Consider, A 1 2 3 1 4 9 118 12 1 9 3 1 4 2 662 ½ 20 A1exists 2 4 1 Matrix of minors= 4 1 2 3 1 3 9 1 9 1 1 1 9 1 9 1 1 1 3 1 3 1 2 1 4 1 1 1 4 1 1 1 2 6 6 2 5 8 3 1 2 1 6 6 2 matrix of cofactors 5 8 3 1 2 1 6 5 1 Adj.A 6 8 2 2 3 1 1 A1 .adj.A A 6 5 1 1 = 6 8 2 2 2 3 1 X A1 B 6 5 1 3 1 = 6 8 2 4 2 2 3 1 6 1 ½ ½ ½ Total Marks MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. Summer 2013 Model answers x 4 2 y = 1 2 1 2 z 0 0 3. Page No: 10/28 Marks 1 OR Matrix of cofactors can be evaluated by following method: 1 (b) Ans. Resolve into partial fractions: x3 2 x2 1 x x 1 x 2 2 3 x3 x + x2 3 x 2 x2 2 x 2 x 1 x 1 x2 x2 Consider, 2 x 1 x 1 x 1 1 x2 A B x 1 x 1 x 1 x 1 ½ x 2 x 1 A x 1 B Total Marks 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. Summer 2013 Model answers Page No: 11/28 Marks Total Marks Put x 1 3. 1 2 A 1 2 Put x 1 A 1 3=2B B (c) Ans. 3 2 1 x2 1/ 2 3/ 2 x 1 x 1 x 1 x 1 x3 2 1/ 2 3/ 2 x 2 x 1 x 1 x 1 Resolve into partial fractions: ½ 04 ex e2 x 4e x 3 put e x t t t t 4t 3 t 3 t 1 2 t A B t 3 t 1 t 3 t 1 t t 1 A t 3 B ½ ½ put t 3 3 2 A 3 A 2 put t 1 1 1 2 B 1 B= 2 t t 3 t 1 1 3 / 2 1/ 2 t 3 t 1 ex 3 / 2 1/ 2 x x x e 3 e 1 e 3 e x 1 ½ ½ 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. 3. (d) Page No: 12/28 Model answers Marks Total Marks In any ABC,prove that sin Ans. Summer 2013 A B C BC A C A B sin sin cos A cos B cos C 2 2 2 A B C 180 A B 180 C A B C 180 2C A B C 90 C 2 A B C sin sin 90 C 2 1 A B C sin cos C 2 1 Similarly, BC A sin cos A 2 C A B sin cos B 2 ½ ½ A B C BC A C A B sin sin sin 2 2 2 = cosA+cosB+cosC (e) If A and B are both obtuse angles and sin A 1 5 4 and cos B , 13 5 then find sin( A B). Ans. Given sin A 5 5 13 cos B 13 4 5 3 5 A 12 cos A 12 13 , B 4 sin B 3 5 1 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. Summer 2013 Model answers Page No:13/28 Marks Total Marks A and B are obtuse 3. 12 3 , sin B 13 5 sin( A B) sin A.cos B cos A.sin B cos A 5 4 12 3 . . 13 5 13 5 56 = 65 1 1 1 04 OR Given sin A 5 13 cos A 1 sin 2 A = 1 25 169 12 13 A and B are obtuse = 12 13 4 and cosB= 5 cos A = 1 sin B 1 cos 2 B = 1 = sin B 16 25 3 5 3 5 B is obtuse 1 sin A B sin A.cos B cos A.sin B 5 4 12 3 . . 13 5 13 5 -56 = 65 = (f) 4 8 84 Prove that sin 1 sin 1 sin 1 5 17 85 1 1 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. 3. Summer 2013 Model answers sin A Page No: 14/28 Marks Total Marks 4 5 cos A 1 sin 2 A = 1 = 16 25 3 5 1 and sin B = 8 17 cos B 1 cos 2 B = 1 64 289 15 17 LHS=A B 1 = RHS= sin 1 84 85 Consider, sin( A B) sin A.cos B cos A.sin B 4 15 3 8 84 = . . 5 17 5 17 85 1 4 8 84 84 A B sin 1 sin 1 sin 1 A B sin 1 5 17 85 85 OR 4 A 5 4 sin A 5 Let sin 1 , , 8 =B 17 8 sin B 17 sin -1 1 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. Summer 2013 Page No: 15/28 Model answers Marks 3. 4 5 8 17 3 tan A 4 3 A tan 1 sin 1 15 , 4 3 4 4 tan 1 5 3 1 , , 8 15 8 B tan 1 15 8 8 sin 1 tan 1 17 15 tan B 1 4 8 sin 1 5 17 4 8 tan 1 tan 1 3 15 4 8 tan 1 5 15 4 8 1 . 5 15 60 24 tan 1 45 45 32 45 84 tan 1 13 LHS sin 1 84 85 84 Let sin 1 C 85 84 sin C 85 1 ½ RHS= sin 1 84 85 13 Total Marks MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. 3. Summer 2013 Model answers Page No: 16/28 Marks Total Marks 84 13 84 C tan 1 13 84 84 sin 1 tan 1 85 13 tan C ½ 84 RHS= tan 13 LHS=RHS 04 1 16 Attempt any four of the following: 4. (a) Ans. Prove that tan A B tan A tan B 1 tan A.tan B ½ 2 1 ½ 04 (b) Ans. 1 1 1 1 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. 4. (c) Summer 2013 Model answers Page No: 17/28 Marks Total Marks Without using calculator show that Ans. 1 1 ½ ½ 1 Note: give appropriate marks for another method. (d) Prove that Ans. 1 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. Summer 2013 Model answers Page No: 18/28 Marks Total Marks 4. 1 1 1 (e) 04 Prove that Ans. 2 1 ½ ½ (f) Ans. Prove that 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. Summer 2013 Page No: 19/28 Model answers Marks Total Marks 4. 2 1 1 04 OR Note : This example can be solved by another method , see question no.3 (f) on page.no.15. Attempt any Four of the following: 5. (a) Prove that 1 Ans. 1 1 1 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. 5. Summer 2013 Page No: 20/28 Model answers Marks Total Marks (b) 1 1 1 1 04 (c) Ans. 1 -(1) 1 1 from(1) (d) 1 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. 5. Ans. Summer 2013 Page No: 21/28 Model answers Marks Total Marks 1 Y-axis P( ) X-axis is 1 1 1 (e) Ans. 1 1 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. Summer 2013 Model answers Page No: 22/28 Marks Total Marks 5. 1 1 04 (f) Ans. 3x = 9 1 1 1 1 2 1 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. Summer 2013 Model answers 5. Page No: 23/28 Marks 1 Total Marks 04 Attempt any Four of the following: 6. (a) Ans. 1 from fig. 1 1 . 1 (b) Ans. 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. Summer 2013 Page No: 24/28 Model answers Marks Total Marks 6. 1 1 ½ 1 ½ (c) Find the range and coefficient of range of the following data: Age (in years) Frequency 1019 2029 3039 4049 5059 6069 7079 03 61 223 137 53 19 04 1 1 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. Summer 2013 Page No: 25/28 Model answers Marks Total Marks 6. 1 1 (d) 04 Find mean deviation from median for the following data: Class 0 10 10 20 20 30 30 40 40 50 5 8 15 16 6 interval Freauency Ans. Class 0 5 5 25 22 110 10 15 8 120 12 96 20 25 15 375 2 30 30 35 16 560 8 12 40 45 6 270 18 108 50 1350 1 472 1 1 1 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. 6. e) Summer 2013 Page No: 26/28 Model answers Marks Total Marks Find variance and coefficient of variance for the following data: Class 0- Interval 5 Frequency 3 510 1015 1520 2025 2530 3035 3540 5 9 15 20 16 10 2 Class Ans. 0-5 2.5 3 7.5 6.25 18.75 5-10 7.5 5 37.5 56.25 281.25 10-15 12.5 9 112.5 156.25 1406.25 15-20 17.5 15 262.5 306.25 4593.75 20-25 22.5 20 450 506.25 10125 25-30 27.5 16 440 756.25 12100 30-35 32.5 10 325 1056.25 10562.5 35-40 37.5 2 75 1406.25 2812.5 80 1710 1 41900 `1 1 04 1 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. 6. Summer 2013 Page No: 27/28 Model answers Marks Total Marks Class 0-5 2.5 3 -3 -9 9 27 5-10 7.5 5 -2 -10 4 20 10-15 12.5 9 -1 -9 1 9 15-20 17.5 a 15 0 0 0 0 20-25 22.5 20 1 20 1 20 25-30 27.5 16 2 32 4 64 30-35 32.5 10 3 30 9 90 35-40 37.5 2 4 8 16 32 80 4 62 1 262 1 1 1 04 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC - 27001 - 2005 Certified) ______________________________________________________________________________________________ Subject Code: (17104) Que. Sub. No. Que. Summer 2013 Page No: 28/28 Model answers Marks Total Marks 6. Note: Students may take any another value for A in the above/below example. So the above table and corresponding values vary accordingly. But the final answer will be the same. (f) The two sets of observations are given below: Set-I Set-II Which of the two sets is more consistent? 1½ 1½ 1 Important Note In the solution of the question paper, wherever possible all the possible alternative methods of solution are given for the sake of convenience. Still student may follow a method other than the given herein. In such case, first see whether the method falls within the scope of the curriculum, and then only give appropriate marks in accordance with the scheme of marking. 04
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