In Exercises 41–48, the rectangular coordinates of a point are given. Find polar coordinates of each point. Express θ in radians. (−2, 2)
Ch. 5 - Complex Numbers, Polar Coordinates and Parametric Equations

All textbooks
Blitzer 3rd Edition
Ch. 5 - Complex Numbers, Polar Coordinates and Parametric Equations
Problem 43
Blitzer 3rd Edition
Ch. 5 - Complex Numbers, Polar Coordinates and Parametric Equations
Problem 43Chapter 5, Problem 43
In Exercises 37–52, perform the indicated operations and write the result in standard form. __ (−3 − √−7)²
Verified step by step guidance1
Recognize that the expression involves a complex number because of the term \( \sqrt{-7} \). Recall that \( \sqrt{-7} = \sqrt{7}i \), where \( i \) is the imaginary unit with the property \( i^2 = -1 \). So rewrite the expression as \( (-3 - \sqrt{7}i)^2 \).
Use the formula for squaring a binomial: \( (a - b)^2 = a^2 - 2ab + b^2 \). Here, \( a = -3 \) and \( b = \sqrt{7}i \).
Calculate each term separately: \( a^2 = (-3)^2 \), \( -2ab = -2 \times (-3) \times (\sqrt{7}i) \), and \( b^2 = (\sqrt{7}i)^2 \).
Simplify each term carefully, remembering that \( i^2 = -1 \). This will help convert the imaginary squared term into a real number.
Combine the simplified terms to write the result in standard 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:
4mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Complex Numbers and Imaginary Unit
Complex numbers consist of a real part and an imaginary part, expressed as a + bi, where i is the imaginary unit with the property i² = -1. Understanding how to handle the square root of negative numbers, such as √-7 = i√7, is essential for working with complex expressions.
Recommended video:
Introduction to Complex Numbers
Algebraic Operations on Complex Numbers
Performing operations like addition, subtraction, multiplication, and exponentiation on complex numbers requires applying algebraic rules while treating i as a variable with the special property i² = -1. Squaring a complex binomial involves expanding using the distributive property or FOIL method.
Recommended video:
Adding and Subtracting Complex Numbers
Standard Form of a Complex Number
The standard form of a complex number is a + bi, where a and b are real numbers. After performing operations, the result should be simplified and expressed clearly in this form, separating the real and imaginary parts for clarity and further use.
Recommended video:
Complex Numbers In Polar Form
Related Practice
Textbook Question
794
views
Textbook Question
In Exercises 37–52, perform the indicated operations and write the result in standard form. ___ −8 + √−32 / 24
731
views
Textbook Question
In Exercises 41–48, the rectangular coordinates of a point are given. Find polar coordinates of each point. Express θ in radians. _ (2,−2√3)
720
views
Textbook Question
In Exercises 65–68, find all the complex roots. Write roots in polar form with θ in degrees. The complex cube roots of 8(cos 210° + i sin 210°)
610
views
Textbook Question
In Exercises 37–44, find the product of the complex numbers. Leave answers in polar form. z₁ = cos π/4 + i sin π/4 z₂ = cos π/3 + i sin π/3
545
views
Textbook Question
In Exercises 35–44, test for symmetry and then graph each polar equation. r = 2 + 3 sin 2θ
925
views