Match the vector fields (a)--(f) with their flow lines (1)--(6). Determine which direction the flow moves along the flow lines.

(a) $-y\,\vec i + x\,\vec j$ : flow lines ? 1 2 3 4 5 6
(b) $x\,\vec i + y\,\vec j$ : flow lines ? 1 2 3 4 5 6
(c) $y\,\vec i + x\,\vec j$ : flow lines ? 1 2 3 4 5 6
(d) $(x-y)\vec i + (x-y)\vec j$ : flow lines ? 1 2 3 4 5 6
(e) $-y\,\vec i + (x + y/10)\vec j$ : flow lines ? 1 2 3 4 5 6
(f) $-y\,\vec i + (x - y/10)\vec j$ : flow lines ? 1 2 3 4 5 6

1.		2.		3.
4.		5.		6.