Westonci.ca offers fast, accurate answers to your questions. Join our community and get the insights you need now. Our Q&A platform provides quick and trustworthy answers to your questions from experienced professionals in different areas of expertise. Explore comprehensive solutions to your questions from knowledgeable professionals across various fields on our platform.

If the expression below is rewritten in the form [tex]$a+bi$[/tex], where [tex]$a$[/tex] and [tex][tex]$b$[/tex][/tex] are real numbers, what is the value of [tex]$a$[/tex]? (Note: [tex]$i=\sqrt{-1}$[/tex])

[tex]\frac{8-i}{3-2i}[/tex]


Sagot :

To solve the expression [tex]\(\frac{8 - i}{3 - 2i}\)[/tex] in the form [tex]\(a + bi\)[/tex], where [tex]\(a\)[/tex] and [tex]\(b\)[/tex] are real numbers, we need to simplify it. Here is the step-by-step procedure to rewrite it and identify the value of [tex]\(a\)[/tex]:

1. Complex Conjugate Multiplication:
Multiply both the numerator and the denominator by the conjugate of the denominator. The conjugate of [tex]\(3 - 2i\)[/tex] is [tex]\(3 + 2i\)[/tex].

Thus, the expression becomes:
[tex]\[ \frac{(8 - i)(3 + 2i)}{(3 - 2i)(3 + 2i)} \][/tex]

2. Simplify the Denominator:
The denominator is a difference of squares which simplifies as follows:
[tex]\[ (3 - 2i)(3 + 2i) = 3^2 - (2i)^2 = 9 - 4i^2 = 9 - 4(-1) = 9 + 4 = 13 \][/tex]

3. Expand the Numerator:
Next, expand the numerator:
[tex]\[ (8 - i)(3 + 2i) = 8 \cdot 3 + 8 \cdot 2i - i \cdot 3 - i \cdot 2i \][/tex]
Simplify each term:
[tex]\[ = 24 + 16i - 3i - 2i^2 = 24 + 13i - 2(-1) = 24 + 13i + 2 = 26 + 13i \][/tex]

4. Divide Terms in the Numerator by the Denominator:
Now, divide each part of the complex number by the denominator 13:
[tex]\[ \frac{26 + 13i}{13} = \frac{26}{13} + \frac{13i}{13} = 2 + i \][/tex]

5. Identify [tex]\(a\)[/tex] and [tex]\(b\)[/tex]:
The resulting expression is [tex]\(2 + i\)[/tex]. Here we can see the real part [tex]\(a\)[/tex] is [tex]\(2\)[/tex] and the imaginary part [tex]\(b\)[/tex] is [tex]\(1\)[/tex].

Thus, in the expression [tex]\(\frac{8 - i}{3 - 2i} = 2 + i\)[/tex], the value of [tex]\(a\)[/tex] is:
[tex]\[ \boxed{2} \][/tex]