Mar Dionysius Senior Sec. School Rishi Valley, Mallappally, Kerala, India-689534 Paper : x1 mat Mathematical Induction Q.1 Using the principle of mathematical induction, prove that n(n + 1) is a multiple of 2, for all n Q.2 Solve by induction that 1 . 3 + 2 . 32 + 3 . 33 + ...+ n . 3n = Q.3 (Marks : 3 (Marks : 3 ) Prove by induction that An= cosn , when it is given that A1= cos > 2, the relations Am = 2Am - 1cos N. - Am - 2 hold true. , A2 = cos2 and for every natural number m (Marks : 3 ) Q.4 For a natural number m, let A be a set having m elements. Prove that p(A), the power set of A, has 2m elements. (Marks : 4 ) Q.5 If n is a positive integer, prove that (Marks : 4 ) Q.6 Q.7 Prove that (3 + )n + (3 - )n is an integer, for all n N. (Marks : 4 ) For any natural number n > 1, prove (Marks : 4 ) Q.8 Use induction to prove that n(n2 - 1) is divisible by 24, if n is any odd positive integer. Q.9 Prove the identity: If x is not a multiple of 2 (Marks : 4 ) use mathematical induction to prove that cosx + cos2x + ... + cosnx Q.10 Show that 10n + 3 . 4n + 2+ 5 is divisible by 9 for each natural number n. Q.11 Let u1 = 1, u2 = 1, un + 2 = un + 1 + un for n 1, use mathematical induction to shows that for all n Q.12 (Marks : 6 ) 1. (Marks : 6 ) Prove by mathematical induction that (Marks : 6 ) Q.13 Prove by the method of induction that 7 + 77 + 777... . (Marks : 6 ) Q.14 Prove the identity: Let 0 < Ai < sinAn n for i = 1, 2, ..., n, then sinA1 + sinA2 + ... where n 1 is a natural number. (Marks : 6 ) Q.15 For all positive integers n, prove that Q.16 is an integer. (Marks : 6 ) Using induction or otherwise, prove that for any non-negative integers m, n, r and k, (Marks : 6 )