Identifying Real Numbers

Which of the following is a real number: 5, √-4, π, i?

• -3

• √4

• 5, π

• 2i

Is -3.14 a real number?

• Yes, -3.14 is a real number.

• No, -3.14 is not a real number.

• -3.14 is an imaginary number.

• -3.14 is a complex number.

Identify the real numbers from the set: {2, 3.5, -1, √2, √-1}.

• √-1

• -2

• {2, 3.5, -1, √2}

• 3

Which of these is not a real number: 0, -7, 4.5, 2i?

• sqrt(-1)

• -2.5

• 3.14

• 2i

Is 0.333... a real number?

• No, 0.333... is not a number at all.

• No, 0.333... is an imaginary number.

• Yes, 0.333... is a whole number.

• Yes, 0.333... is a real number.

Select all real numbers from this list: {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, -2, -3.5, √-9}.

• [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, -2, -3.5]

• -1

• 3.5

• √4

Is the number -√16 a real number?

• Yes

• It depends on the context

• Only in complex numbers

• No

Which of the following is a real number: 7, 8.2, 9.999, 10i?

• 7, 8.2, 9.999

• 10

• -5.5

• 3.14i

Identify the real numbers: {1/2, 3.14, -5, 0, 2.718, 4i}.

• {1/2, 3.14, -5, 0, 2.718}

• 2.5

• -3.14

• 4i

Is 2.5 a real number?

• 2.5 is a complex number but not a real number.

• Yes, 2.5 is a real number.

• No, 2.5 is not a real number.

• 2.5 is an imaginary number.