Absolute Value of Complex numbers (Mini-Lesson)

Absolute Value of Complex numbers (Mini-Lesson)

By Jesus Molina

The Modulus of a Complex Number

Multiple Choice

Find $$\left|3\ -\ 2i\right|$$  

• 13

• $$\sqrt{13}$$  

• 5

• 5i

Multiple Choice

$$\left|a+bi\right|$$  is defined as:

• $$\sqrt{a^2+b^2}$$  

• $$\sqrt{a^2-b^2}$$  

• $$\sqrt{a^2+\left(bi\right)^2}$$  

• $$\sqrt{a^2-\left(bi\right)^2}$$  

Multiple Select

Choose all that apply.  Find $$\left|6+8i\right|$$

• $$\sqrt{\left(6\right)^2-\left(8i\right)^2}$$  

• $$\sqrt{\left(6\right)^2+\left(8\right)^2}$$  

• 10

• 10i

Multiple Choice

Find $$\left|\frac{2-i}{3i}\right|$$  

• 3

• -3

• 5

• $$\frac{\sqrt{5}}{3}$$

Multiple Choice

Find $$\left|\frac{5+2i}{5-2i}\right|$$  

• i

• -1

• 1

• -i

Multiple Choice

$$\left|\frac{2}{\left(-4+12i\right)}\cdot\frac{\left(-1+3i\right)}{1}\right|$$  

what is the absolute value?

• $$\frac{1}{2}$$  

• $$\frac{80}{160}$$  

• $$\frac{8}{16}$$  

• $$\frac{2}{4}$$