Trigonometry (10th Edition)

Published by Pearson
ISBN 10: 0321671775
ISBN 13: 978-0-32167-177-6

Chapter 7 - Applications of Trigonometry and Vectors - Section 7.4 Vectors, Operations, and the Dot Product - 7.4 Exercises - Page 329: 25

Answer

(a) $4\textbf{i}$ (b) $7\textbf{i}+3\textbf{j}$ (c) $-5\textbf{i}+\textbf{j}$

Work Step by Step

(a) To find the value of $2\textbf{u}$, we substitute the vector $\textbf{u}$ in the expression and simplify: $2\textbf{u}=2(2\textbf{i})=4\textbf{i}$ (b) To find the value of $2\textbf{u}+3\textbf{v}$, we substitute the vectors $\textbf{u}$ and $\textbf{v}$ in the expression and simplify: $2\textbf{u}+3\textbf{v}=2(2\textbf{i})+3(\textbf{i}+\textbf{j})=4\textbf{i}+3\textbf{i}+3\textbf{j}=7\textbf{i}+3\textbf{j}$ (c) To find the value of $\textbf{v}-3\textbf{u}$, we substitute the vectors $\textbf{u}$ and $\textbf{v}$ in the expression and simplify: $\textbf{v}-3\textbf{u}=(\textbf{i}+\textbf{j})-3(2\textbf{i})=\textbf{i}+\textbf{j}-6\textbf{i}=-5\textbf{i}+\textbf{j}$
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.