1. Functions

Question 1

What is a set?

Answer 1

A set is a collection of objects / elements.

Question 2

What is the meaning of ℕ?

Answer 2

Natural Numbers (all positive integers excluding zero)

Question 3

What is the meaning of ℕo?

Answer 3

Natural Numbers including zero.

Question 4

What is the meaning of ℤ?

Answer 4

Integers e.g. -1, 0, 1, 2

Question 5

What is the meaning of ℚ?

Answer 5

Rational Numbers e.g. -1, 0, 1, 3/2

Question 6

What is the meaning of ℝ?

Answer 6

Real Numbers e.g. π , -5, root 2

Question 7

What is the meaning of a ∈ A ?

Answer 7

element a belongs to set A

Question 8

What is the meaning of a ∉ A ?

Answer 8

element a does not belong to set A

Question 9

What is the meaning of A ⊆ B ?

Answer 9

A is a subset of B (all elements in A are in B)

Question 10

What is the meaning of A ⊂ B ?

Answer 10

A is a strict subset of B (A is a subset of B and A ≠ B)

Question 11

What is the meaning of ∅ ?

Answer 11

Empty set. The empty set is a strict subset of all sets

Question 12

What is a function?

Answer 12

A function is an expression that maps one set to another set

Question 13

What is the domain?

Answer 13

The domain is the input set

Question 14

What is the codomain?

Answer 14

The codomain is the output set.

Question 15

What is the image?

Answer 15

All elements / numbers that the function can take the value of. The image / range is always a subset of the codomain.

Question 16

What is the range?

Answer 16

All elements / numbers that the function can take the value of. The image / range is always a subset of the codomain.