3. Suppose a,b e Z. If a (b-2b) is odd, then a and b are odd.

Advanced Engineering Mathematics
10th Edition
ISBN:9780470458365
Author:Erwin Kreyszig
Publisher:Erwin Kreyszig
Chapter2: Second-order Linear Odes
Section: Chapter Questions
Problem 1RQ
icon
Related questions
Question

subject: discrete math 

 

ANSWER #3 ONLY

Use the method of contrapositive proof to prove the following statements. (In
each case you should also think about how a direct proof would work. You will
find in most cases that contrapositive is easier.)
1. Suppose n € Z. If n² is even, then n is even.
2. Suppose n e Z. If n² is odd, then n is odd.
3. Suppose a,b € Z. If a²(b²-2b) is odd, then a and b are odd.
4. Suppose a,b,c € Z. If a does not divide be, then a does not divide b.
5. Suppose x € R. If x² +5x<0 then x < 0.
6. Suppose x E R. If x-x>0 then x>-1.
7. Suppose a, b € Z. If both ab and a+b are even, then both a and b are even.
8. Suppose x € R. If x5-4x²+3x³-x²+3x-4≥0, then x≥0.
9. Suppose n € Z. If 3+n², then 3 n.
10. Suppose x,y,ze Z and x 0. If xyz, then xy and xtz.
Transcribed Image Text:Use the method of contrapositive proof to prove the following statements. (In each case you should also think about how a direct proof would work. You will find in most cases that contrapositive is easier.) 1. Suppose n € Z. If n² is even, then n is even. 2. Suppose n e Z. If n² is odd, then n is odd. 3. Suppose a,b € Z. If a²(b²-2b) is odd, then a and b are odd. 4. Suppose a,b,c € Z. If a does not divide be, then a does not divide b. 5. Suppose x € R. If x² +5x<0 then x < 0. 6. Suppose x E R. If x-x>0 then x>-1. 7. Suppose a, b € Z. If both ab and a+b are even, then both a and b are even. 8. Suppose x € R. If x5-4x²+3x³-x²+3x-4≥0, then x≥0. 9. Suppose n € Z. If 3+n², then 3 n. 10. Suppose x,y,ze Z and x 0. If xyz, then xy and xtz.
Expert Solution
steps

Step by step

Solved in 4 steps

Blurred answer
Recommended textbooks for you
Advanced Engineering Mathematics
Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated
Numerical Methods for Engineers
Numerical Methods for Engineers
Advanced Math
ISBN:
9780073397924
Author:
Steven C. Chapra Dr., Raymond P. Canale
Publisher:
McGraw-Hill Education
Introductory Mathematics for Engineering Applicat…
Introductory Mathematics for Engineering Applicat…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY
Mathematics For Machine Technology
Mathematics For Machine Technology
Advanced Math
ISBN:
9781337798310
Author:
Peterson, John.
Publisher:
Cengage Learning,
Basic Technical Mathematics
Basic Technical Mathematics
Advanced Math
ISBN:
9780134437705
Author:
Washington
Publisher:
PEARSON
Topology
Topology
Advanced Math
ISBN:
9780134689517
Author:
Munkres, James R.
Publisher:
Pearson,