Imaginary Numbers

5 flashcards · Mathematics · by lakesare

1. What's a complex number?

   a + ib Complex number has: real part (real number) imaginary part (real number * √−1)

2. What is a square root of -16?

   4i

3. How to explain this contradiction?

   This property DOES NOT hold for negative numbers: https://www.khanacademy.org/math/algebra2/x2ec2f6f830c9fb89:complex/x2ec2f6f830c9fb89:imaginary/v/i-as-the-principal-root-of-1-a-little-technical?modal=1

4. Multiply complex numbers: 2i(3−8i)

   6i + 16 2i(3−8i) = 2i(3) − 2i(8i) = 6i − 16i^2 = 6i + 16

5. What is (4i)2?

   -16