Exploring Complex Numbers in Quadratic Equations

Which of the following is an example of an imaginary concept?

• Dogs

• Unicorns

• Rivers

• Mountains

Why can't the square root of -9 be a real number?

• Because multiplying a number by itself always gives a positive result

• Because multiplying two negative numbers gives a positive result

• Because zero is the only number that can be squared to get a negative result

• Because multiplying two positive numbers gives a negative result

What is the imaginary unit 'i' defined as?

• The square root of 1

• The square root of -1

• The square root of 9

• The square root of 0

What symbol is used to represent the imaginary unit in engineering?

• l

• j

• i

• k

How would you write the square root of -9 using the imaginary unit?

• -3i

• -3

• 3i

• 3

What is a complex number?

• A number that is neither real nor imaginary

• A number that has both real and imaginary parts

• A number that is only real

• A number that is only imaginary

In the complex number 2 + 3i, what is the real part?

• 2

• 3

• i

• 5

In the complex number 2 + 3i, what is the imaginary part?

• 2

• 3

• 5

• i

How would you write the complex number 3 + the square root of -25?

• 3 + 5i

• 3 + 5

• 3 + 25i

• 3 + 5j

What is the imaginary part of the complex number 3 + 5i?

• 8

• 5

• i

• 3