Complex Numbers 1

This lesson introduces the concept of the imaginary number i, which is the square root of -1, and complex numbers. It shows how to simplify square roots of negative numbers, define pure imaginary numbers and identify the real and imaginary parts of a complex number in standard form. The lesson emphasizes that any real number times i is a pure imaginary number, while any number in the form a + bi is a complex number. Overall, this lesson provides a solid foundation for understanding complex numbers.

Introduction to the Imaginary unit (imaginary number) i which is the square root of -1, and complex numbers. Several examples are provided, showing how to simplify square roots of negative numbers, define pure imaginary numbers, state the standard form of a complex number, and identify the real and imaginary parts of a complex number in standard form.

• What are complex numbers?
• What is the imaginary unit i?
• How do you take the square root of a negative number?
• What is standard form of a complex number?
• What are the real and imaginary parts of a complex number?
• What is the square root of -1?
• What is the square root of -9?
• Why does i^2 = -1?
• What is a pure imaginary number?
• What is the square root of -25?
• How do you simplify the square root of -18?