5.71. Below is given a proof of a result. What result is proved? Proof Let a, b, Ce Z such that a² + b² = c². Assume, to the contrary, that a, b and c are all odd. By (the contrapositive of) Theorem 3.12 O, a? and b? are both odd. Therefore, a? = 2r +1 and b = 2s +1 for integers r and s. Thus, a? + b² = 2r + 2s + 2 = 2 (r + s+1). Since r + s+1 is an integer, a? + b is even. However, a? + b² = c² and c2 is odd. This is a contradiction.
5.71. Below is given a proof of a result. What result is proved? Proof Let a, b, Ce Z such that a² + b² = c². Assume, to the contrary, that a, b and c are all odd. By (the contrapositive of) Theorem 3.12 O, a? and b? are both odd. Therefore, a? = 2r +1 and b = 2s +1 for integers r and s. Thus, a? + b² = 2r + 2s + 2 = 2 (r + s+1). Since r + s+1 is an integer, a? + b is even. However, a? + b² = c² and c2 is odd. This is a contradiction.
Elements Of Modern Algebra
8th Edition
ISBN:9781285463230
Author:Gilbert, Linda, Jimmie
Publisher:Gilbert, Linda, Jimmie
Chapter6: More On Rings
Section6.1: Ideals And Quotient Rings
Problem 34E: 34. If is an ideal of prove that the set is an ideal of . The set is called the annihilator of the...
Related questions
Topic Video
Question
what mistakes are found in this proof
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution!
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 2 images
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, advanced-math and related others by exploring similar questions and additional content below.Recommended textbooks for you
Elements Of Modern Algebra
Algebra
ISBN:
9781285463230
Author:
Gilbert, Linda, Jimmie
Publisher:
Cengage Learning,
Algebra & Trigonometry with Analytic Geometry
Algebra
ISBN:
9781133382119
Author:
Swokowski
Publisher:
Cengage
Elementary Geometry For College Students, 7e
Geometry
ISBN:
9781337614085
Author:
Alexander, Daniel C.; Koeberlein, Geralyn M.
Publisher:
Cengage,
Elements Of Modern Algebra
Algebra
ISBN:
9781285463230
Author:
Gilbert, Linda, Jimmie
Publisher:
Cengage Learning,
Algebra & Trigonometry with Analytic Geometry
Algebra
ISBN:
9781133382119
Author:
Swokowski
Publisher:
Cengage
Elementary Geometry For College Students, 7e
Geometry
ISBN:
9781337614085
Author:
Alexander, Daniel C.; Koeberlein, Geralyn M.
Publisher:
Cengage,
College Algebra (MindTap Course List)
Algebra
ISBN:
9781305652231
Author:
R. David Gustafson, Jeff Hughes
Publisher:
Cengage Learning