Questions: Perform the indicated operation.
(5+9 i)(5-9 i)
(5+9 i)(5-9 i)=
(Simplify your answer. Type your answer in the form a + bi.)
Transcript text: / College Algebra with Support / FA24
Complex Numbers
Questi
Perform the indicated operation.
\[
\begin{array}{l}
(5+9 i)(5-9 i) \\
(5+9 i)(5-9 i)=
\end{array}
\]
$\square$
(Simplify your answer. Type your answer in the form a + bi.)
Solution
Solution Steps
To solve the problem of multiplying two complex numbers, we can use the formula for the product of conjugates. The product of a complex number and its conjugate is a real number, calculated as \(a^2 + b^2\), where \(a\) and \(b\) are the real and imaginary parts, respectively. In this case, the numbers are \(5 + 9i\) and \(5 - 9i\).
Step 1: Identify the Complex Numbers
We are given the complex numbers \( (5 + 9i) \) and \( (5 - 9i) \).
Step 2: Apply the Product of Conjugates Formula
The product of a complex number and its conjugate can be calculated using the formula:
\[
(5 + 9i)(5 - 9i) = 5^2 + 9^2
\]