What is linear nonhomogeneous recurrence relation of degree k with constant coefficients? Find all the solutions of the recurrence relation a, 4a+n. Also find the solution of the relation with initial condition a, 1.[10]
2.
Explain product rule. How many strings are there of four lowercase letters that have the letter x in them?[5]
Induction and Recursion
1.
Use mathematical induction to show that the sum of first n positive integers is n(n+1)/2.[5]
Logic and Proof Methods
1.
Explain direct proof, indirect proof, and proof by contradiction. Use direct proof to show that 'If n is an odd integer, then n' is an odd integer'. Also use indirect proof to show that 'If n is an integer and n' then n is odd'.[10]
2.
What is tautology? Show (p∧q)→(p∨q) is a tautology.[5]
Number Theory
1.
What is congruent modulo? Determine whether 20 is congruent to 8 modulo 6 and 25 is congruent to 17 modulo 5.[5]
2.
Explain trial division with example? Using trial division, show that 101 is prime.[5]
Sets, Relations and Functions
1.
Define cartesian product. Find A3 for the set A = (a, b, c).[5]
2.
How can you represent relations using matrices? Suppose that A={1,2,3} and B={1,2}. Let R be the relation from A to B containing (a,b) if a∈A, b∈B, and a>b. What matrix representing R if a1=1, a2=2, a3=3, and b1=1 and b2=2?[5]
Tree and Graphs
1.
Define spanning tree and minimum spanning tree with suitable example. Use Kruskal's algorithms to find minimum spanning tree in the given graph
[10]
2.
What is graph? Explain simple graph and pseudograph with example.[5]
3.
What is Euler path? Compare it with Hamilton path.[5]