Chapter 10: Problem 55
Perform each indicated operation. Write the result in the form \(a+b i\) $$ (1-i)(1+i) $$
Short Answer
Expert verified
The result is 2, in the form 2 + 0i.
Step by step solution
01
Apply the Distributive Property
We'll begin by multiplying
(1 - i)(1 + i) using the distributive property.
Multiply each part of the first complex number by each part of the second complex number:
(1 - i)(1 + i) = 1 * 1 + 1 * i - i * 1 - i * i.
02
Simplify the Expression
Now, simplify the products from the distribution:
1 * 1 = 1,
1 * i = i,
- i * 1 = -i,
- i * i = -i^2.
Combine these:
1 + i - i - i^2.
03
Simplify Using the Property of i
Recall that
(-i^2) simplifies to +1 because
(i^2 = -1).
Therefore, the expression becomes:
1 + i - i + 1.
04
Combine Like Terms
Now, combine like terms:
1 + 1 = 2,
and the terms
i - i = 0.
The result is 2.
05
Write in the Form a + bi
Since there is no imaginary part left in the expression, the result in the form
a + bi
is
2 + 0i.
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Distributive Property in Complex Numbers
The distributive property is a fundamental concept in algebra that allows us to multiply a sum by distributing the multiplication over each term within the parentheses. For example, when we see the expression \((a + b)(c + d)\), this multiplication distributes as \((a \cdot c + a \cdot d + b \cdot c + b \cdot d)\).
With complex numbers, the process is similar, but you need to carefully track the imaginary unit \(i\) while performing these operations.
In the exercise \((1 - i)(1 + i)\), applying the distributive property means multiplying each term in \((1 - i)\) by each term in \((1 + i)\).
Therefore, the result is:
With complex numbers, the process is similar, but you need to carefully track the imaginary unit \(i\) while performing these operations.
In the exercise \((1 - i)(1 + i)\), applying the distributive property means multiplying each term in \((1 - i)\) by each term in \((1 + i)\).
Therefore, the result is:
- \(1 \cdot 1\)
- \(1 \cdot i\)
- \(-i \cdot 1\)
- \(-i \cdot i\).
Simplification of Complex Expressions
Simplifying expressions in complex numbers is essential after distributing terms. The main goal here is to reduce the expression to a simpler form.
From \( (1 - i)(1 + i) \), we obtain: \(1 + i - i - i^2\).
The terms \(1 \cdot 1,\) \(1 \cdot i,\) \(-i \cdot 1,\) and \(-i \cdot i\) were computed during distribution and the result was gathered as \(1 + i - i - i^2\).
The imaginary parts \(i\) and \(-i\) cancel each other since \(i - i = 0\).
So simplifying further leads us to handle the \(-i^2\) term next.
From \( (1 - i)(1 + i) \), we obtain: \(1 + i - i - i^2\).
The terms \(1 \cdot 1,\) \(1 \cdot i,\) \(-i \cdot 1,\) and \(-i \cdot i\) were computed during distribution and the result was gathered as \(1 + i - i - i^2\).
The imaginary parts \(i\) and \(-i\) cancel each other since \(i - i = 0\).
So simplifying further leads us to handle the \(-i^2\) term next.
Understanding and Using the Imaginary Unit
The imaginary unit, denoted as \(i,\) is a special constant with the property that \(i^2 = -1\).
This property is crucial in simplifying complex number expressions.
In the expression \(1 + i - i - i^2,\) we know \(-i^2\) actually translates to \(+1\) because \(i^2 = -1\) implies \(-i^2 = -(-1) = 1\).
Remembering this crucial property allows us to modify \(-i^2\) into a real number addition, changing the expression to \(1 + 1\).
Understanding how \(i\) works makes handling complex operations simpler.
This property is crucial in simplifying complex number expressions.
In the expression \(1 + i - i - i^2,\) we know \(-i^2\) actually translates to \(+1\) because \(i^2 = -1\) implies \(-i^2 = -(-1) = 1\).
Remembering this crucial property allows us to modify \(-i^2\) into a real number addition, changing the expression to \(1 + 1\).
Understanding how \(i\) works makes handling complex operations simpler.
Performing Algebraic Operations with Complex Numbers
Algebraic operations on complex numbers often involve combining like terms to reach a simplified result.
Like terms in the context of complex numbers are those involving the imaginary unit \(i\) and those that do not.
When the expression \(1 + i - i + 1\) is simplified and results in \(1 + 1 = 2\), we're left purely with a real number.
The imaginary components \(i\) and \(-i\) cancel each other out, resulting in zero.
After canceling and combining like terms, we are left with the simplified form \(2 + 0i\), which is the final form \(a + bi\) of the expression.
The beauty of algebraic operations lies in transforming a seemingly complex math problem into a straightforward answer.
Like terms in the context of complex numbers are those involving the imaginary unit \(i\) and those that do not.
When the expression \(1 + i - i + 1\) is simplified and results in \(1 + 1 = 2\), we're left purely with a real number.
The imaginary components \(i\) and \(-i\) cancel each other out, resulting in zero.
After canceling and combining like terms, we are left with the simplified form \(2 + 0i\), which is the final form \(a + bi\) of the expression.
The beauty of algebraic operations lies in transforming a seemingly complex math problem into a straightforward answer.