Q31P - Mathematical Methods in Physical Sciences

Question

Use Problems 27 and 28 to find the following absolute values. If you understand Problems 27 and 28 and equation (5.1), you should be able to do these in your head.

 $\left|5e^{2\mathrm{\pi i}/3}\right|$

Step-by-Step Solution

Answer

The absolute value of the expression ${\text{|5e}}^{2\mathrm{\pi i}/3}|=5$  .

Step 1: Given information

The given complex number is ${\text{|5e}}^{2\mathrm{\pi i}/3}|$  .

Step 2: Definition of complex numbers.

The numbers that are presented in the form of $\mathbf{a}\mathbf{+}\mathbf{ib}\mathbf{ }$where a,b are real numbers and is an imaginary number called complex numbers.

Step 3: Use the result concluded in problem 27.

Let the complex number  $5e^{2\mathrm{\pi i}/3}$ be  .                                                                   ……. (1)

 

Use the result concluded in problem 27.

 $$\begin{gathered} R=\left|z\right| \\ R=\left|r{e}^{\left(i\theta \right)}\right| \\ R=r \end{gathered}$$

                                                                                                                      …….(2)

Compare equations (1) and (2) as:

 $R=5.$

 Hence the absolute value of the expression $\left|5e^{2\mathrm{\pi i}/3}\right|=5.$