Mathematical Proof Equations

Question 1

For a number to be odd

Answer 1

n = 2k + 1, where k is a whole integer.

Question 2

For a number to be even

Answer 2

n = 2k, where k is a whole integer.

Question 3

For a number to be rational

Answer 3

n = k / l where k and l are both integers and l does not equal 0.

Question 4

For a number to be irrational.

Answer 4

There is no equation, but can be represented as Pi or √2.