Vector Product Question (Mathematical Methods in Physics Course)

[melampyge]

Hey guys,

I can't solve the first two problems. Can you help me please ASAP?

http://img694.imageshack.us/img694/5562/hw1e.jpg

 

[marcusl]

Per the forum guidelines, please show your work in attempting to solve the problem.

 

[melampyge]

In the first question i just substitute the vector B in the equation B=del cross A and find it but in the second question it asks me to find A. That's the problem.