Name of the school Grade: ---- Chapter Name – Work Sheet number Date: -------- Time: Estimated Time to Complete Name of Student: Date of Submission: Maths assignment XII RELATIONS AND FUNCTIONS 5 −7 1. If π(π₯) = [π₯] and (π₯) = |π₯| , then evaluate (πππ) (2) − (πππ) ( 2 ). 1 2. If π(π₯) = (3 − π₯ 3 )3 and (π₯) = log π π₯ , find πππ(π₯). 3. Let * be a binary operation defined by a*b = 2ab – 7. Is * associative? 4. Let π΄ = {1,2,3} and = {4,5,6} , π: π΄ → π΅ is a function defined on π(1) = 4 , π(2) = 5 and π(3) = 6. Write the inverse of f as a set of ordered pairs. 5. Let ‘*’ be a binary operation defined on the set Z as a a*b = a+b+1 for a,b ∈ I. find the identity element. π₯−1 6. If π(π₯) = ; π₯ ≠ −1 , then find π −1 (π₯). π₯+1 7. Show that the signum function given by π(π₯) = 1, if x is greater than 0, if x=0, -1 , if x is less than 0 is neither one-to-one nor onto. 8. If π: π → π , a,b,c,d ∈ R such that ( a,b ) * ( c,d ) = (ac, b+ad ). Find the identity element. 9. Give an example for a relation which is neither reflexive nor symmetric. 10. Consider π, π βΆ π → π and β βΆ π → π defined as π(π₯) = 2π₯ , π(π¦) = 3π¦ + 4 , and β(π§) = π πππ§ for all x,y,z ∈ N. Show that ho(gof) = (hog)of. 11. Let A = R X R and let * be a binary operation on A defined by ( a,b )*( c,d ) = ( ad+bc , bd ) for all ( a,b ) , ( c,d ) ∈ R X R. Determine if * is commutative , associative , has identity and inverse. 12. Let A = {-1 , 0 , 1 , 2 } , B = [ -4 , -2 , 0 , 2 } and π, π βΆ π΄ → π΅ be the function defined by 1 π(π₯) = π₯ 2 − π₯, π₯ ∈ π΄ and π(π₯) = 2 |π₯ − 2| − 1 , π₯ ∈ π΄ ; are f and g equal ? Justify your answer. 5π₯+3 13. If π(π₯) = 4π₯−5, show that f(f(x)) is an identity function. 14. Let π(π₯) = [π₯] and π(π₯) = |π₯|. Find −5 −5 (i) (πππ) ( ) − (πππ) ( ) 3 5 5 3 (ii) (πππ) (3) − (πππ) (3) Subject / Grade / Work Sheet Number / Chapter Number / 2012-2013 Page 1 (iii) (π + 2π)(−1) 15. Check whether the relation R defined in the set {1,2,3,4,5,6} as R = { (a,b) : b = a+1 } is reflexive, symmetric or transitive. 16. Show that the relation S in the set given by S = { (a,b : |a-b| is even } is an equivalence relation. Also find the set of all elements related to 4. 1 17. If f(x) = (3 − π₯ 3 )3 , find f(f(x)). 18. If π, π: π → π are defined respectively by π(π₯) = π₯ 2 + 3π₯ + 1 , π(π₯) = 2π₯ − 3. Find (i) fog (ii) gof (iii) fof (iv) gog. 19. If the function π: π → π defined by π(π₯) = 2π₯ 3 + 7, prove that f is one-one and onto function. Also find the inverse of the function π and π −1 (23). 20. If P(X) is the power set of the set X, and A*B=A∪B, find the identity if it exists. π+π π+π 21. Examine if the following are binary operations (i) a*b = 2 , a,b ∈ N (ii) a*b = 2 , a,b ∈ Q. 22. Consider π: π → [5, ∞) given by π(π₯) = 9π₯ 2 + 6π₯ − 5. Show that f is invertible and (π¦+6)−1 π −1 (π¦) = √ 3 . 23. Let A = N X N and R be the relation on A defined by ( a,b ) R ( c,d ) => (ππ(π + π) = ππ(π + π)). Show that R is an equivalence relation. 24. Let A = N X N and * be the binary operation on A defined by ( a,b )*( c,d ) = ( a+c,b+d ). Show that * is commutative and associative. Find the identity element for * on A, if any. −3 2π₯ 25. Let π: π − { 5 } → π be a function define as π(π₯) = 5π₯+3 , find π −1 : range of f: π − −3 { 5 }. 26. Consider π: {1,2,3} → {π, π, π} and π: (π, π, π} → {πππππ, ππππ, πππ‘} defined by f(1)= a, f(2) =b . f(3)=c , g(a)= apple, g(b)=ball , g(c)=cat. Show that f,g and gof are invertible. Find out π −1 , π−1 and (πππ)−1 and show that (πππ)−1 = π −1 o π−1 . 27. Prove that the function π: π → π defined as π(π₯) = 2π₯ − 3 is invertible and π −1 (π₯). 28. Show that the relation are in the set a = { x : x ∈ w , x≤ 10 } given by R = { (a,b) : |ab| is a multiple of 3 } is an equivalence relation , find the elements related to 3. INVERSE TRIGONOMETRIC FUNCTIONS 1 5 √2 1. Find 2π‘ππ−1 ( ) + π ππ −1 ( 5 2. Solve for x : π₯−1 7 1 ) + 2π‘ππ−1 (8) π₯+1 (i) π‘ππ−1 ( ) + π‘ππ−1 (π₯+2) = π₯−2 1−π₯ 1 π‘ππ−1 ( ) = π‘ππ−1 π₯ 1+π₯ 2 −1 (πππ π₯) −1 π 4 (ii) (iii) 2π‘ππ = π‘ππ (2πππ πππ₯) π −1 −1 (iv) π ππ π₯ + π ππ 2π₯ = (v) π ππ −1 (1 (vi)πππ‘ −1 3 −1 − π₯) − 2π ππ π₯ = π₯ − πππ‘ −1 (π₯ + 2) = π 2 π 12 Subject / Grade / Work Sheet Number / Chapter Number / 2012-2013 Page 2 (vii) π‘ππ−1 ( 2π₯+1 1−4 π₯ −1 2 ) (viii) π ππ (π₯ √1 − π₯ 2 − π₯√1 − π₯ 4 3. Simplify : 1 (i) π‘ππ−1 ( π ππ−1 ( 2π₯ 1 1−π¦ 3 )) + 2 πππ −1 (1+π¦2 ) 1+π₯ 2 2 π₯−π₯ −1 (ii) πππ −1 ( −1) π₯+π₯ −1 (iii) π‘ππ (√1 + π₯ 2 − π₯) 4. Prove that: 12 4 63 (i) π ππ−1 ( ) + πππ −1 ( ) + π‘ππ−1 ( ) = π 13 5 16 (ii) πππ −1 π₯ + πππ −1 π¦ + πππ −1 π§ = π , prove that π₯ 2 + π¦ 2 + π§ 2 + 2π₯π¦π§ = 1 π₯ π₯2 π¦ (iii) πππ −1 ( ) + πππ −1 ( )=πΌ, prove that 2 − π π π 1 2 1 3 (iv) π‘ππ−1 ( ) + π‘ππ−1 ( ) = πππ −1 ( ) 4 9 2 5 4 5 16 2π₯π¦ ππ πππ πΌ + π¦2 π2 = π ππ2 πΌ π (v) π ππ−1 ( ) + π ππ−1 ( ) + π ππ−1 ( ) = 5 13 65 2 2 (π‘ππ−1 2 (πππ‘ −1 (vi) π ππ 2) + πππ ππ 3) = 15 −1 −1 −1 (vii) π‘ππ π₯ + π‘ππ π¦ + π‘ππ π§ = π, prove that π₯ + π¦ + π§ = π₯π¦π§ MATRICES 1. If A = [πππ ] , where [πππ ] = { π + π , ππ π ≥ π , construct a 3 X 2 matrix A. π − π ππ π < π 3 −2 ) , then find k if π΄2 = kA – 2I. 4 −2 Construct a 3 X 2 matrix whose elements in the ith row and jth column are given by π+4π πππ = 2 . 2 3 If f(x) = π₯ 2 − 4π₯ + 1 , find f(A) , when A = [ ]. 1 2 1 −2 5 4 Find the matrix X , for which [ ] X=[ ]. 1 3 π 1 1 π(π −1) π π π If A = [ ] , π ≠ 1 , prove that π΄π = [ π π−1 ] , n∈N . 0 1 0 1 3 1 For the matrix A = [ ] , find a and b such that π΄2 + ππΌ = ππ , where I is a 2 X 2 7 5 identity matrix . 0 −1 1 −1 Find X and Y , given that 3X - Y = [ ] and X - 3Y = [ ]. 0 −1 −1 1 3 1 If A = [ ] , show that π΄2 -5A + 7I = 0 , hence find π΄−1 . −1 2 2. If A = ( 3. 4. 5. 6. 7. 8. 9. Subject / Grade / Work Sheet Number / Chapter Number / 2012-2013 Page 3 −1 10. If A = [ 2 ] , B = [-2 -1 -4] , verify that (AB)’= B’A’ . 3 11. If A = ( cos π π sin π π sin π ) , then prove by principle of Mathematical Induction that cos π cos ππ π sin ππ π΄π = [ ]. π sin ππ cos ππ 12. Express the following matrix as the sum of a symmetric and a skew-symmetric matrix 1 3 5 : [−6 8 3] . −4 6 5 2 4 5 4 13. If A = [ ] , B =[ ] , then verify that (AB)’= B’A’. 3 5 3 2 3 2 5 14. Let A = [4 1 3] . Express A as a sum of two matrices such that one is symmetric 0 6 7 and the other is skew-symmetric. 15. Using elementary transformations , find the inverse of the following matrix : 1 2 3 [2 5 7 ]. −2 −4 −5 3 6 5 2 16. Find the matrices X and Y , if X + Y =[ ] and X – Y = [ ] and hence find π 2 − 0 −1 0 9 π2 . 17. Show that the matrix B’AB is symmetric or skew symmetric according as A is symmetric or skew symmetric. DETERMINANTS π2 + 2π 1. Using properties of determinants, prove that : | 2π + 1 3 π2 2ππ π 2 2. Show that : | π 2 π2 2ππ | = (π3 + π 3 )2 . 2ππ π 2 π2 0 1 1 3. Find π΄−1 , if π΄ = [1 0 1]. Also show that π΄−1 = 1 1 0 π΄2 −3πΌ 2 2π + 1 1 π + 2 1| = (π − 1)3 . 3 1 . 4. Using properties of determinants, prove that : π+π |π + π π+π π+π π+π π+π π+π π + π | = 2(π + π + π)(ππ + ππ + ππ − π2 − π 2 − π 2 ). π+π Subject / Grade / Work Sheet Number / Chapter Number / 2012-2013 Page 4 π ππ(π΄ + π΅ + πΆ) −π πππ΅ 5. If π΄ + π΅ + πΆ = π , show that [ cos(π΄ + π΅) π πππ΅ 0 −π‘πππ΄ π+π 6. Prove using the properties of determinants : | π + π π+π . πππ πΆ π‘πππ΄] = 0 . 0 π+π π+π π+π π+π π | = 2 | π+π π π+π π π π π π π| π 7. Using the properties of determinants prove that : (π + π)2 | π2 π2 π2 (π + π)2 π2 π2 +π 2 π π 8. Show that : π2 π 2 | = 2πππ (π + π + π)3 . (π + π)2 | | π π | π | π2 +π 2 π π 2 +π2 π π π 9. Using the properties of determinants , show that : π |π + 2π π+π π+π π π + 2π π + 2π π + π | = 9π 2 (π + π). π 2 3 10 π₯ π¦ π§ 10. Solve for x,y,z : − + 4 6 5 6 9 20 π₯ π¦ π§ π₯ π¦ π§ =4; − + =1; + − =2. 11. Using the properties of determinants , prove the following : π |π − π π+π π π−π π+π 12. Solve for x , | 13. If A = [ π π − π | = π3 + π 3 + π 3 − 3πππ. π+π 3π₯ − 8 3 3 1 −π‘πππ₯ 3 3π₯ − 8 3 3 3 | = 0. 3π₯ − 8 π‘πππ₯ πππ 2π₯ ] , show that π΄′ π΄−1 = [ 1 π ππ2π₯ −π ππ2π₯ ]. πππ 2π₯ 14. Using the properties of determinants, prove that : −ππ 2 (i) | π + ππ π2 + ππ π 2 + ππ −ππ π 2 + ππ π 2 + ππ π 2 + ππ| = (ππ + ππ + ππ)3 . −ππ Subject / Grade / Work Sheet Number / Chapter Number / 2012-2013 Page 5 π (ii) | π ππ₯ + ππ¦ π π ππ₯ + ππ¦ π+π 15. Show that : |π + π π+π ππ₯ + ππ¦ ππ₯ + ππ¦ | = (π 2 − ππ)(ππ₯ 2 + 2ππ₯π¦ + ππ¦ 2 ). 0 π−π π−π π−π π π | = 3πππ − π3 − π 3 − π 3 . π CONTINUITY AND DIFFERENTIABILITY 1. Discuss the continuity : π₯ ,π₯ ≠ 0 2|π₯| (a) π(π₯) = { 1 ,π₯ = 0 2 3 2 1 −π₯, 3 (b) π(π₯) = 2 3 ≤π₯<1 2 ,π₯ = 1 +π₯ ,π₯ > 1 { 2 πππ 3π₯−πππ π₯ (c) π(π₯) = { ,π₯ ≠ 0 π₯2 −4 , π₯ = 0 , π₯≠1 π₯−1 [π₯]−1 (d) π(π₯) = { −1 , π₯ = 1 2. Find the value of k such that the function ‘f’ is continuous : ππππ π₯ π ,π₯ ≠ 2 π−2π₯ (a) π(π₯) = { π 3,π₯ = 2 1−π ππ3 π₯ 3πππ 2 π₯ ,π₯ < π ,π₯ = (b) π(π₯) = π(1−π πππ₯) { (π−2π₯)2 1−πππ 4π₯ π π 2 2 ,π₯ > π 2 ,π₯ < 0 π ,π₯ = 0 π₯2 (c) π(π₯) = √π₯ {√16+√π₯−4 ,π₯ > 0 sin(π+1)π₯+π πππ₯ π₯ π ,π₯ = 0 (d) π(π₯) = { √π₯+ππ₯ 2 −√π₯ π₯−5 π₯−|5| (e) π(π₯) = ,π₯ < 0 π√π₯ 3 ,π₯ > 0 + π ,π₯ < 5 π + π ,π₯ = 5 π₯−5 {π₯−|5| + π , π₯ > 5 Subject / Grade / Work Sheet Number / Chapter Number / 2012-2013 Page 6 π₯ 2 −3π₯+2 (f) π(π₯) = { π₯ 2 −1 2 3 ,π₯ ≠ 1 π ,π₯ = 1 1. If y=sin−1 (π₯√1 − π₯ − √π₯ √1 − π₯ 2 ) or sin−1(π₯ 2 √1 − π₯ 2 − π₯√1 − π₯ 4 ) π¦ ππ¦ π₯+π¦ 2. If log(π₯ 2 + π¦ 2 ) = 2 tan−1 (π₯ ) , show that ππ₯ = π₯−π¦ 3. If π₯ = π(πππ π + ππ πππ), π¦ = π(π πππ − ππππ π), find π ππ2 (π+π¦) ππ¦ π2 π¦ ππ₯ 2 4. If π πππ¦ = π₯π ππ(π + π¦), prove that ππ₯ = π πππ 5. Differentiate π₯ πππ π₯ + π πππ₯ π‘πππ₯ ππ¦ −π¦ −1 −1 6. π₯ = √πsin π‘ , π¦ = √πcos π‘ , prove that = ππ₯ π₯ 7. π¦ = 3 cos(ππππ₯) + 4 sin(ππππ₯), prove that π₯ 2 π¦2 + π₯π¦1 + π¦ = 0 −1 8. π¦ = π π sin π₯ , prove that (1 − π₯ 2 )π¦2 − π₯π¦1 − π2 π¦ = 0 3π₯+4√1−π₯ 2 9. π¦ = cos−1 ( 5 ππ¦ ) , find ππ₯ 2π₯+1 ππ¦ 10. π¦ = cos−1 (1+4π₯ ) , find ππ₯ ππ¦ 11. π¦ = log10 (ππππ πππ₯) , find ππ₯ π π 12. π¦ = log tan ( + ), show that 13. π(π₯) = 4 2 −1 1−π₯ tan (1+π₯) ππ¦ ππ₯ π₯+2 = π πππ₯ − tan−1 (1−2π₯) , find π ′ (π₯) π‘ π2 π¦ 14. π₯ = π(πππ π‘ + log π‘ππ 2 ) , π¦ = π(1 + π πππ‘), find ππ₯ 2 15. π¦ = (cot −1 π₯)2 , prove that (π₯ 2 + 1)2 π¦2 + (2π₯)(π₯ 2 + 1)π¦1 − 2 = 0 1. If π₯ = π πππ‘ , π¦ = π ππππ‘ , prove that (1 − π₯ 2 )π¦2 π₯. π¦1 + π2 π¦ = 0 ππ¦ ππππ₯ 2. π₯ π¦ = π π₯−π¦ , prove that ππ₯ = (1+ππππ₯)2 ππ¦ −1 3. π₯√1 + π¦ + π¦√1 + π₯ = 0 , prove that ππ₯ = (1+π₯)2 4. √1 − π₯ 6 + √1 − π¦ 6 = π(π₯ 3 − π¦ 3 ), prove that ππ¦ ππ¦ ππ₯ = π₯ 2 √1−π¦6 π¦ 2 √1−π₯ 6 π¦ 5. π₯ π π¦ π = (π₯ + π¦)π+π , prove that ππ₯ = π₯ π2 π¦ 6. π¦ = πππ‘π₯ + πππ πππ₯, prove that prove that (1 − πππ π₯)2 ππ₯ 2 = π πππ₯ 1−π₯ ππ¦ −π₯ 7. If π¦ = π ππ (2 tan−1 (√1+π₯)) ,prove that ππ₯ = √1−π₯ 2 √1+π₯ 2 −√1−π₯ 2 8. Differentiate tan−1 (√1+π₯ 2 9. π¦ = π₯.π ππ4 π₯ √1−π₯ 2 +√1−π₯ 2 ) w.r.t tan−1(√1 + π₯ 2 − π₯) ππ¦ + πππ(√1 − π₯ 2 ) prove that ππ₯ = sin−1 π₯ 3 (1−π₯ 2 )2 Subject / Grade / Work Sheet Number / Chapter Number / 2012-2013 Page 7 .. ∞ ππ¦ 10. π¦ = π πππ₯ π πππ₯ , find ππ₯ 2 11. π¦ = (log(π₯ + √π₯ 2 + 1)) prove that (π₯ 2 + 1)π¦2 + π₯π¦1 − 2 = 0 12. If π¦ = π ππ₯ π ππππ₯, prove that π¦2 − 2ππ¦1 + (π2 + π 2 )π¦ = 0 13. If π¦ = sin(π sin−1 π₯), prove that prove that (1 − π₯ 2 )π¦2 − π₯π¦1 + π2 π¦ = 0 1 14. If π₯ = sin (π log π¦) , prove that (1 − π₯ 2 )π¦2 − π₯π¦1 + π2 π¦ = 0 15. Find the points of discontinuity , π(π₯) = |π₯| − |π₯ + 1| 16. Verify mean value theorem , π(π₯) = π ππ4 π₯ + πππ 4 π₯ π(π₯) = (π₯ 2 − 4π₯ + 3)π 2π₯ 17. Verify Rolle’s theorem , π(π₯) = (π₯ − 1)(π₯ − 2)2 π(π₯) = πππ π₯ + π πππ₯ π [0, 2 ] [1,3] [1,2] [0,2π] VECTORS 1. If πβ + πββ + πβ = 0, show that πβ × πββ = πββ × πβ = πβ × πβ. 2. If πβ × πββ = πβ × πβ, πβ × πβ = πββ × πβ, prove that (πβ − πβ) β₯ (πββ − πβ) , πβ ≠ π , πββ ≠ πβ. 3. Prove that |πβ × πββ|2 = |πβ|2 |πββ|2 − (πβ. πββ)2 , |πβ| = 5 , |πββ| = 3, |πβ × πββ| = 25, find (πβ. πββ). 4. The dot product of a vector with vectors πΜ + πΜ − 3πΜ , πΜ + 3πΜ − 2πΜ , 2πΜ + πΜ + 4πΜ are 0 , 5 and 8. Find the vector. 5. Show that 2πΜ − πΜ + πΜ , πΜ − 3πΜ − 5πΜ and 3πΜ − 4πΜ − 4πΜ form the sides of a right angled triangle. 6. Find the unit vector perpendicular to the plane ABC , position vectors of A , B and C are 2πΜ − πΜ + πΜ , πΜ + πΜ + 2πΜ and 2πΜ + 3πΜ respectively. 7. Express πβ = 5πΜ − 2πΜ + 5πΜ as the sum of two vectors such that one is ββββ parallel to the vector πββ = 3πΜ + πΜ and the other is perpendicular to π. 8. If πβ = πΜ + 2πΜ − 3πΜ , πββ = 3πΜ − πΜ + 2πΜ , show that (i) (πβ + πββ) ⊥ (πβ − πββ) (ii) Find a unit vector perpendicular to both (πβ + πββ) and (πβ − πββ). 9. Find the projection of πββ + πβ on πβ , where πβ = 2πΜ − 2πΜ + πΜ , πββ = πΜ + 2πΜ − 2πΜ and πβ = 2πΜ − πΜ + 4πΜ. 10.If πβ = πΜ + πΜ + πΜ , πββ = πΜ − πΜ , find a vector πβ such that πβ × πβ = πββ , πβ. πβ = 3. 11.If πβ + πββ + πβ = 0 , |πβ| = 3 , |πββ| = 5 , |πβ| = 7 , find the angle between πβ πππ πββ. 12.If πβ. πββ = πβ. πβ and πβ × πββ = πβ × πβ , πβ ≠ 0, prove that πββ = πβ. Subject / Grade / Work Sheet Number / Chapter Number / 2012-2013 Page 8 13.If πβ , πββ , πβ are position vectors of A , B and C of βπ΄π΅πΆ, show that 1 (i) area of βπ΄π΅πΆ = |πβ × πββ + πββ × πβ + πβ × πβ| 2 (ii) deduce the condition of collinear. 14.If πβ × πββ = πββ × πβ, show that πβ + πβ = ππββ , where m is a scalar. 15.If πβ is a unit vector , (π₯β − πβ). (π₯β + πβ) = 8 , find |π₯|. 16.Find the area of βπ΄π΅πΆ , A(1,1,1) , π΅(1,2,3), πΆ(2,3,1). 17.If |πβ| = 3 , |πββ| = 4 , |πβ| = 5 and one of them is perpendicular to the sum of other two, find |πβ + πββ + πβ|. ββββ, πβ are mutually 18.If If πβ × πββ = πβ , πββ × πβ = πβ , prove that πβ , π perpendicular, |πββ| = 1 , |πβ| = |πβ|. π 1 π 1 19.If πΜ , πΜ are unit vectors , prove that sin = |πβ − πββ| , cos = |πβ + πββ |. 2 2 2 2 20.If πβ , πββ , πβ are of equal magnitude and mutually perpendicular , show that πβ + πββ + πβ is equally inclined to πβ , πββ , πβ . π 21.πβ , πββ , πβ are unit vectors πβ. πββ = πβ. πβ = 0 , angle between πββ πππ πβ is . 6 Prove that πβ = ±2(πββ × πβ). 22.If the sum of two unit vectors is a unit vector , prove that magnitude of their difference is √3. 23.Find the area of the parallelogram whose diagonals are 3πΜ + πΜ − 2πΜ and πΜ − 3πΜ + 4πΜ. 24. Prove that πβ × (πββ + πβ) + πββ × (πβ + πβ) + πβ × (πβ + πββ) = β0β. ************* Subject / Grade / Work Sheet Number / Chapter Number / 2012-2013 Page 9 Rubrics Criteria being evaluated Criteria being evaluated Task is complete Task is incomplete Answers is complete Answer is not complete with some confusion Subject / Grade / Work Sheet Number / Chapter Number / 2012-2013 Task is not completed Answer is not correct. student needs teachers support to complete the task Page 10