Match the following expressions with their correct answers.

1. [tex] j^7 [/tex]
2. [tex] j^8 [/tex]
3. [tex] j^4 [/tex]
4. [tex] j^3 [/tex]
5. [tex] j^6 [/tex]
6. [tex] j^2 [/tex]
7. [tex] j^5 [/tex]

A. -1



Answer :

Sure! Let's match each of the given expressions with their correct answers based on what we know about powers of the imaginary unit [tex]\( j \)[/tex] (where [tex]\( j \)[/tex] represents [tex]\(\sqrt{-1}\)[/tex] or [tex]\( i \)[/tex]).

Given:
[tex]$j^7, j^8, j^4, j^3, j^6, j^2, j^5$[/tex]

And their possible values:
[tex]$1, -1, j, -j$[/tex]

### Step-by-Step Solution:

1. Determine [tex]\( j^7 \)[/tex]:
- [tex]\( j^7 = -j \)[/tex] or written as [tex]\( -i \)[/tex].

2. Determine [tex]\( j^8 \)[/tex]:
- [tex]\( j^8 = 1 \)[/tex].

3. Determine [tex]\( j^4 \)[/tex]:
- [tex]\( j^4 = 1 \)[/tex].

4. Determine [tex]\( j^3 \)[/tex]:
- [tex]\( j^3 = -j \)[/tex] or written as [tex]\( -i \)[/tex].

5. Determine [tex]\( j^6 \)[/tex]:
- [tex]\( j^6 = -1 \)[/tex].

6. Determine [tex]\( j^2 \)[/tex]:
- [tex]\( j^2 = -1 \)[/tex].

7. Determine [tex]\( j^5 \)[/tex]:
- [tex]\( j^5 = j \)[/tex] or written as [tex]\( i \)[/tex].

Now, we straightforwardly match these results with the given expressions:

[tex]$\underline{\space} \ j^7 \quad (-j)$[/tex]
[tex]$j^8 \quad (1)$[/tex]
[tex]$j^4 \quad (1)$[/tex]
[tex]$j^3 \quad (-j)$[/tex]
[tex]$j^6 \quad (-1)$[/tex]
[tex]$\underline{\space} \ j^2 \quad (-1)$[/tex]
[tex]$\underline{\space} \ j^5 \quad (j)$[/tex]

### Let's fill them into the original expressions correctly:

1. [tex]\( j^7 = -j \)[/tex]
- The box before [tex]\( j^7 \)[/tex]:
[tex]$-\boxed{j}$[/tex]

2. [tex]\( j^8 = 1 \)[/tex]

3. [tex]\( j^4 = 1 \)[/tex]

4. [tex]\( j^3 = -j \)[/tex]
- The box before [tex]\( j^3 \)[/tex]:
[tex]$-\boxed{j}$[/tex]

5. [tex]\( j^6 = -1 \)[/tex]

6. [tex]\( j^2 = -1 \)[/tex]
- The box before [tex]\( j^2 \)[/tex]:
[tex]$\boxed{-1}$[/tex]

7. [tex]\( j^5 = j \)[/tex]
- The box before [tex]\( j^5 \)[/tex]:
[tex]$\boxed{j}$[/tex]

Hence, plugging these into their boxes:

[tex]\[ \begin{align*} &(-j) \quad j^8 \quad j^4 \quad (-j) \quad j^6 \quad (-1) \quad j^5 \\ \end{align*} \][/tex]

Now I am going to summarize it more neatly:

[tex]$ -j \ j^7 $[/tex]
[tex]$ j^8 = 1 $[/tex]
[tex]$ j^4 = 1 $[/tex]
[tex]$ -j \ j^3 $[/tex]
[tex]$ j^6 = -1 $[/tex]
[tex]$ -1 \ j^2 $[/tex]
[tex]$ j^5 $[/tex]