Precalculus: Mathematics for Calculus, 7th Edition

Published by Brooks Cole
ISBN 10: 1305071751
ISBN 13: 978-1-30507-175-9

Chapter 9 - Section 9.1 - Vectors in Two Dimensions - 9.1 Exercises - Page 637: 32

Answer

$2\vec{u}=\langle-4,10\rangle$ $-3\vec{v}=\langle-6,24\rangle$ $\vec{u}+\vec{v}=\langle0,-3\rangle$ $3\vec{u}-4\vec{v}=\langle-14,47\rangle$

Work Step by Step

$\vec{u}=\langle-2,5\rangle,$ $\vec{v}=\langle2,-8\rangle$ $2\vec{u}$ Multiply both components of the vector $\vec{u}$ by $2$: $2\vec{u}=2\langle-2,5\rangle=\langle-4,10\rangle$ $-3\vec{v}$ Multiply both components of the vector $\vec{v}$ by $-3$: $-3\vec{v}=-3\langle2,-8\rangle=\langle-6,24\rangle$ $\vec{u}+\vec{v}$ Add the same component of both vectors together and simplify: $\vec{u}+\vec{v}=\langle-2,5\rangle+\langle2,-8\rangle=\langle-2+2,5-8\rangle=\langle0,-3\rangle$ $3\vec{u}-4\vec{v}$ Multiply the vector $\vec{u}$ by $3$ and the vector $\vec{v}$ by $-4$ and then evaluate the operation: $3\vec{u}-4\vec{v}=3\langle-2,5\rangle-4\langle2,-8\rangle=\langle-6,15\rangle+\langle-8,32\rangle=...$ $...=\langle-6-8,15+32\rangle=\langle-14,47\rangle$
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.