1. Lecture 1.6: Proof Techniques (contd)
CS 250, Discrete Structures, Fall 2014
Nitesh Saxena
Adopted from previous lectures by Cinda Heeren

2. Lecture 1.6 - Proof Techniques (contd.)
Course Admin
HW1
Due at 11am on Sep 18
Please follow all instructions
Questions?
4/14/2019
Lecture Proof Techniques (contd.)

3. Lecture 1.6 - Proof Techniques (contd.)
Outline
Proof Techniques (more examples)
4/14/2019
Lecture Proof Techniques (contd.)

4. Lecture 1.6 - Proof Techniques (contd.)
Black Board Exercises
Prove the following:
If n is an integer and n2 is odd, then n is odd.
If m and n are both perfect squares, then nm is also a perfect square.
If n is an integer and n3 + 5 is odd, then n is even
If m and n are integers, and mn is even, then m is even or n is even
If n is a positive integer, then n is even if and only if 7n + 4 is even
Sqrt(2) is irrational
4/14/2019
Lecture Proof Techniques (contd.)

5. Lecture 1.6 - Proof Techniques (contd.)
Today’s Reading
Rosen 1.7
Please solve the exercises at the end of each chapter section. They are fun.
4/14/2019
Lecture Proof Techniques (contd.)