# Complex Numbers 2

Taught by YourMathGal
• Currently 4.0/5 Stars.
2066 views | 2 ratings
Part of video series
Meets NCTM Standards:
Lesson Summary:

In this lesson on complex numbers, we learn how to simplify square roots of negative numbers, and multiply and divide with imaginary and complex numbers. We are reminded of the definitions of i and the rules for simplifying square roots, including rewriting them in the form BI. The lesson also emphasizes the importance of not leaving negative numbers under the square root sign and rewriting them as the square root of a positive number times i. The video provides several examples to help reinforce these concepts.

Lesson Description:

Several examples are provided, showing how to simplify square roots of negative numbers, and multiply and divide with imaginary and complex numbers.

More free YouTube videos by Julie Harland are organized at http://yourmathgal.com

• What is a complex number?
• How do you compute square roots of negative numbers?
• What is the square root of -50?
• What is 5*sqrt(-45)?
• What is -6*(square root of -9)?
• What is sqrt(-11)*sqrt(-11)?
• What is the square root of -41 times the square root of -41?
• What is the square root of -2 times the square root of -8?
• What is the square root of -6 times the square root of -10?
• What is the square root of -18 divided by the square root of 2?
• What is the square root of -1?
• Why isn't the square root of a negative times the square root of a negative equal to a positive?
• #### Staff Review

• Currently 4.0/5 Stars.
This video shows a bunch of example problems for simplifying square roots of negative numbers that are multiplied or divided. The steps involved in simplifying these expressions are explained very well. This is a great way to try out the complex number skills that you have just learned.