maths random stuff

Question 1

What does the solid dot mean on an inequality number line?

Answer 1

It means the number is included.

Question 2

What does the hollow dot mean on an inequality number line?

Answer 2

Not including the number, but the fraction or decimal still counts.

Question 3

When do we use this ∈ symbol

Answer 3

When there are no brackets in the first number. It can also mean “X is in set Y”

Question 4

when do we use this ⊂ symbol

Answer 4

When there are brackets on the first number. It can also mean “X is in set T”