Chapter 6.5, Problem 11E

To determine

To find:the absolute value and plot the complex number.

Answer to Problem 11E

The absolute value is $9$ .

Explanation of Solution

Given:

  $\text{z=9i}$ .

Concept used:

Steps to solve the inverse of matrix by

Step1: calculating the matrix of minors.

Step2: turn that into the matrix of cofactors.

Step3: then ad jugate by transposing the cofactor.

Calculation:

Consider the complex number $\text{z=9i}$

The above complex number can be written as $\text{z=0+9i}$

The plot complex number $\text{z=9i}$ as shown in below:

  

The absolute value of $\text{z=9i}$ is given by

  $\left|z\right|=\sqrt{0^2+9^2}$

  $\Rightarrow \sqrt{81}=9.$

Hence the absolute value is $9$ .