Exercicios resolvidos James Stewart vol. 2 7ª ed - ingles

16 0 VECTOR CALCULUS
16.1 Vector Fields
1. F (x, y) = 0.3 i - 0.4j
All vectors in this field are identical, with length 0.5 and
parallel to (3, -:-4) .
3. F (x,y) = - ~ i + (y - x) j
y
The length of the vector - ~ i + (y - x) j is
vt. + (y - x) 2 . Vectors along the line y =X are
horizontal with length ~.
5 F ( ) - y i + x j
. x,y - Jx2 +y2
The length of the vector ~ is 1.
x2 + y2
7. F (x, y , z) = k
All vectors in this field are parallel to the z-axis and have
length 1.
9. F(x,y,z) = x k
At each point (x, y, z), F (x, y, z) is a vector of length lxl.
For x > 0, all point in the direction of the positive z-axis,
while for x < 0, all are in the direction of the negative
z-axis. In each plane x = k, all the vectors are identical.
X
,,
]j
© 2012 Ccnii,OII,C Lco.ming. AU Righrs Rcscm:d. Moy not be scanned. copied, ordup~ cotcd, or posted too publicly occcssiblc website, in whole or in part. 303