Skip to main content
Ch. 5 - Complex Numbers, Polar Coordinates and Parametric Equations
Blitzer - Trigonometry 3rd Edition
Blitzer3rd EditionTrigonometryISBN: 9780137316601Not the one you use?Change textbook
Chapter 5, Problem 5.27

In Exercises 21–28, divide and express the result in standard form.


2+3i / 2+i

Verified step by step guidance
1
Identify the given complex division problem: \(\frac{2+3i}{2+i}\), where \(i\) is the imaginary unit with the property \(i^2 = -1\).
To divide complex numbers, multiply the numerator and denominator by the conjugate of the denominator. The conjugate of \$2+i\( is \)2 - i$.
Multiply numerator and denominator by the conjugate: \(\frac{2+3i}{2+i} \times \frac{2 - i}{2 - i} = \frac{(2+3i)(2 - i)}{(2+i)(2 - i)}\).
Expand both numerator and denominator using the distributive property (FOIL method): - Numerator: \((2)(2) + (2)(-i) + (3i)(2) + (3i)(-i)\) - Denominator: \((2)(2) + (2)(-i) + (i)(2) + (i)(-i)\).
Simplify the expressions by combining like terms and using \(i^2 = -1\), then write the result in the form \(a + bi\), where \(a\) and \(b\) are real numbers.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Complex Number Division

Dividing complex numbers involves expressing the quotient in a form that separates real and imaginary parts. This is typically done by multiplying numerator and denominator by the conjugate of the denominator to eliminate the imaginary part from the denominator.
Recommended video:
4:22
Dividing Complex Numbers

Complex Conjugate

The complex conjugate of a number a + bi is a - bi. Multiplying a complex number by its conjugate results in a real number, specifically a^2 + b^2, which helps simplify division by removing the imaginary component from the denominator.
Recommended video:
5:33
Complex Conjugates

Standard Form of a Complex Number

The standard form of a complex number is a + bi, where a is the real part and b is the imaginary part. Expressing results in this form makes it easier to interpret and use complex numbers in further calculations.
Recommended video:
04:47
Complex Numbers In Polar Form