Webwork questions 4/13/14

Why would x*i be wrong?

and

I have only attempted this problem twice, but I'm not really sure how to
even go about solving a problem like this. If you could please explain and
expand that would help. Thank you.

*********************************************
Well for one thing, i is parallel to the x-axis and you need something parallel to the y-axis.

Edit: it looks like I need to be a little more clear with this.

First of all, two dimensional vector fields look like

;

for every (x,y), P(x,y), and Q(x,y) are both numbers, the x-component of V is P and the y-component is Q.  The direction of the vector field at a point depends on the relative size of P and Q, which have all vectors parallel to an axis would have one of the components equal to zero.  On the other hand, if
 i.e. if P(x,y)=P(x) and Q(x,y)=Q(x),  (or respectively if  , i.e. if P(x,y)=P(y) and Q(x,y)=Q(y)) thenwill be independent of y, respectively will be independent of x. 

*********************************************

For those with java problems with their webwork: please follow the instructions below.
Caveat & Disclaimer: the Java security exceptions are there because there is a real security risk due to persistent security loopholes in the Java platform.  You are responsible for maintaining the security of your own machine, not the university.  When you are done using Java for this problem, you may wish to reverse the process and disable Java.


*********************************************

Dear MAT 267 instructors,

the latest versions of Java have increased security settings that will prevent execution of the applet that creates interactive 3d figures in some of our webwork sets (such as MAT 267).  To fix it, 

Go to the Java Control Panel (on Windows click Start and then Configure Java)
Click on the Security tab
Click on the Edit Site List Button
Click the Add in the Exception Site List window and enter
https://webwork2.asu.edu
Click Add again and enter
https://webwork.asu.edu

You might want to send these instructions to all the students.