Episode 03 – Gaussian integers
European section – Season 3
Episode 03 – Gaussian integers
Gaussian integers on a lattice
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc
Gaussian integers on a lattice
bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc
b
0
Episode 03 – Gaussian integers
Gaussian integers on a lattice
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc
b
0
b
1
Gaussian integers on a lattice
bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc
b
0
b
1
b i
Episode 03 – Gaussian integers
Gaussian integers on a lattice
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc
b
0
b
1
b i
b
2 3i
Gaussian integers on a lattice
bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc
b
0
b
1
b i
b
2 − 3i
b
−4 + 4i
Episode 03 – Gaussian integers
Gaussian integers on a lattice
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc
b
0
b
1
b i
b
2 3i
b
−4 + 4i
b
3 + 2i
Operations in the set of Gaussian integers
Definition (Gaussian integers)
A Gaussian integer is a number of the form a + bi where a and b are two integers and i is an imaginary number such that i 2 = − 1. The set of all Gaussian integers is usually noted Z [i ].
Episode 03 – Gaussian integers
Operations in the set of Gaussian integers
Definition (Gaussian integers)
A Gaussian integer is a number of the form a + bi where a and b are two integers and i is an imaginary number such that i 2 = − 1. The set of all Gaussian integers is usually noted Z [i ].
Golden rule
Addition and multiplication in the set Z [i ] follow the same rules as
addition and multiplication of integers but “real parts” and “imaginary
parts” cannot be mixed up in addition.
Addition and multiplication of points ?
Question 1
What is the graphical effect of adding a Gaussian integer to another ?
Episode 03 – Gaussian integers
Addition and multiplication of points ?
Question 1
What is the graphical effect of adding a Gaussian integer to another ?
Question 2
What is the graphical effect of multiplying a Gaussian integer by
another ?
Addition and multiplication of points ?
Question 1
What is the graphical effect of adding a Gaussian integer to another ?
Question 2
What is the graphical effect of multiplying a Gaussian integer by another ?
Study the problem for :
Episode 03 – Gaussian integers
Addition and multiplication of points ?
Question 1
What is the graphical effect of adding a Gaussian integer to another ?
Question 2
What is the graphical effect of multiplying a Gaussian integer by another ?
Study the problem for :
multiplication by a real number b ;
Addition and multiplication of points ?
Question 1
What is the graphical effect of adding a Gaussian integer to another ?
Question 2
What is the graphical effect of multiplying a Gaussian integer by another ?
Study the problem for :
multiplication by a real number b ; multiplication by the imaginary number i ;
Episode 03 – Gaussian integers
Addition and multiplication of points ?
Question 1
What is the graphical effect of adding a Gaussian integer to another ?
Question 2
What is the graphical effect of multiplying a Gaussian integer by another ?
Study the problem for :
multiplication by a real number b ;
multiplication by the imaginary number i ;
multiplication by the imaginary number bi.
Addition and translation
bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc
b b b
0 i
1
Episode 03 – Gaussian integers
Addition and translation
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc
b b b
0 i
1
b
2 + i
Addition and translation
bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc
b b b
0 i
1
b
2 + i
Episode 03 – Gaussian integers
Addition and translation
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc
b b b
0 i
1
b
2 + i
b
4 3i
Addition and translation
bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc
b b b
0 i
1
b
2 + i
b
− 4 − 3i
b
−2 − 2i
Episode 03 – Gaussian integers
Addition and translation
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc
b b b
0 i
1
b
2 + i
b
4 3i
b
−2 − 2i
Addition and translation
bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc
b b b
0 i
1
b
2 + i
b
− 4 − 3i
b
−2 − 2i
b
1 − 4i
Episode 03 – Gaussian integers
Addition and translation
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc
b b b
0 i
1
b
2 + i
b
4 3i
b
−2 − 2i
b
3 − 3i
Addition and translation
bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc
b b b
0 i
1
b
2 + i
b
− 4 − 3i
b
−2 − 2i
b
1 − 4i
b
3 − 3i
Episode 03 – Gaussian integers
Addition and translation
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc
b b b
0 i
1
b
2 + i
b
4 3i
b
−2 − 2i
b
3 − 3i
b
−5 + 2i
Addition and translation
bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc
b b b
0 i
1
b
2 + i
b
− 4 − 3i
b
−2 − 2i
b
1 − 4i
b
3 − 3i
b
−5 + 2i
b − 3 + 3i
Episode 03 – Gaussian integers
Addition and translation
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc
b b b
0 i
1
b
2 + i
b
4 3i
b
−2 − 2i
b
3 − 3i
b
−5 + 2i
b − 3 + 3i
Multiplication, homothety and rotation
bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc
b b b
b
− 2 + i
Episode 03 – Gaussian integers
Multiplication, homothety and rotation
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc
b b b
b
− 2 + i
b
−4 + 2i
Multiplication, homothety and rotation
bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc
b b b
b
− 2 + i
b
−4 + 2i
Episode 03 – Gaussian integers
Multiplication, homothety and rotation
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc
b b b
b
− 2 + i
b
−4 + 2i
0
Multiplication, homothety and rotation
bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc
b b b
b
− 2 + i
b
−4 + 2i
0
b
3 + i
Episode 03 – Gaussian integers
Multiplication, homothety and rotation
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc
b b b
b
− 2 + i
b
−4 + 2i
0
b
3 + i
b − 1 + 3i
Multiplication, homothety and rotation
bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc
b b b
b
− 2 + i
b
−4 + 2i
0
b
3 + i
b − 1 + 3i
Episode 03 – Gaussian integers
Multiplication, homothety and rotation
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc
b b b
b
− 2 + i
b
−4 + 2i
0
b
3 + i
b − 1 + 3i
b
−2 − 2i
Multiplication, homothety and rotation
bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbcbcbc
b b b
b
− 2 + i
b
−4 + 2i
0
b
3 + i
b − 1 + 3i
b
−2 − 2i
b
4 − 4i
Episode 03 – Gaussian integers
Multiplication, homothety and rotation
bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc bcbcbcbcbcbcbcbcbc