In Exercises 1–10, indicate if the point with the given polar coordinates is represented by A, B, C, or D on the graph. (3, 225°)
Ch. 5 - Complex Numbers, Polar Coordinates and Parametric Equations

All textbooks
Blitzer 3rd Edition
Ch. 5 - Complex Numbers, Polar Coordinates and Parametric Equations
Problem 1
Blitzer 3rd Edition
Ch. 5 - Complex Numbers, Polar Coordinates and Parametric Equations
Problem 1Chapter 5, Problem 1
In Exercises 1–3, perform the indicated operations and write the result in standard form. (6 − 7i)(2 + 5i)
Verified step by step guidance1
Recall that to multiply two complex numbers, we use the distributive property (FOIL method): \((a + bi)(c + di) = ac + adi + bci + bdi^2\).
Apply the distributive property to \((6 - 7i)(2 + 5i)\): multiply each term in the first parenthesis by each term in the second parenthesis.
Calculate each product: \(6 \times 2\), \(6 \times 5i\), \(-7i \times 2\), and \(-7i \times 5i\).
Remember that \(i^2 = -1\), so replace \(i^2\) with \(-1\) in the expression.
Combine the real parts and the imaginary parts separately to write the result in standard form \(a + bi\).

Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Complex Number Multiplication
Multiplying complex numbers involves using the distributive property (FOIL method) to expand the product. Each term in the first complex number is multiplied by each term in the second, combining like terms and applying the rule i² = -1 to simplify.
Recommended video:
Multiplying Complex Numbers
Standard Form of a Complex Number
The standard form of a complex number is expressed as a + bi, where a is the real part and b is the imaginary part. After multiplication, the result should be simplified and rearranged to clearly separate the real and imaginary components.
Recommended video:
Complex Numbers In Polar Form
Imaginary Unit Properties
The imaginary unit i is defined such that i² = -1. This property is essential when simplifying products involving i, as it allows conversion of i² terms into real numbers, enabling the expression to be written in standard form.
Recommended video:
Imaginary Roots with the Square Root Property
Related Practice
Textbook Question
834
views
Textbook Question
In Exercises 1–8, add or subtract as indicated and write the result in standard form. (7 + 2i) + (1 − 4i)
685
views
Textbook Question
In Exercises 1–8, parametric equations and a value for the parameter t are given. Find the coordinates of the point on the plane curve described by the parametric equations corresponding to the given value of t. x = 3 − 5t, y = 4 + 2t; t = 1
894
views
Textbook Question
In Exercises 1–10, perform the indicated operations and write the result in standard form. (8 − 3i) − (17 − 7i)
746
views
Textbook Question
In Exercises 1–3, perform the indicated operations and write the result in standard form. 5 / 2−i
765
views
Textbook Question
In Exercises 1–10, plot each complex number and find its absolute value. z = 4i
561
views