Differential Equations and Linear Algebra (4th Edition)

Published by Pearson
ISBN 10: 0-32196-467-5
ISBN 13: 978-0-32196-467-0

Chapter 6 - Linear Transformations - 6.6 Chapter Review - Additional Problems - Page 429: 2

Answer

See below

Work Step by Step

Assume $x=(x_1,x_2,x_3)\\ y=(y_1,y_2,y_3)\\ c\in R$ $T(x+y)=T((x_1,x_2,x_3)+(y_1,y_2,y_3))\\ =T(x_1+y_1,x_2+y_2,x_3+y_3)\\ =(2(x_1+y_1)-3(x_2+y_2),-(x_1+y_1))\\ =(2x_1++2y_1-3x_2-3y_2,-x_1-y_1)\\ =(2x_1-3x_2,-x_1)+(2y_1-3y_2,-y_1)\\ =T(x_1,x_2,x_3)+T(y_1,y_2,y_3)\\ =T(x)+T(y)$ $T(cx)=T(c(x_1,x_2,x_3))\\ =T(cx_1,cx_2,cx_3)\\ =(2cx_1-3cx_2,-cx_1)\\ =c(2x_1-3x_2,-x_1)\\ =cT(x_1x_2,x_3)\\ =cT(x)$ Hence, $T$ is a linear transformation Obtain: $Ker(T)=\{x \in R^3:T (x)=0\}\\ =\{(x,y,z) \in R^3: T(x,y,z)=0\}\\ =\{(z,y,z) \in R^3: (2x-3y,-x)=(0,0)\\ \rightarrow x=y=0$ then $Ker(T)=\{(0,0,z)\}=\{z(0,0,1)\}=span \{(0,0,1)\}\\ \rightarrow \dim [Ker(T)]=1 \ne 0$ $T$ is not one-to-one (1) Apply Rank Nullity Theorem: $\dim [Ker(T)]+\dim [Rng(T)]=\dim R^3\\ 1+\dim [Rng(T)]=3\\ \dim [Rng(T)]=2$ $Rng(T) \subset R^2$ and $\dim R^2=2=\dim [Rng(T)]$ $T$ is onto (2) Basic for $Rng(T)$ is $\{(1,0),(0,1)$
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.