What is the curl of F for given vector fields?

[hallnate]

Homework Statement

1.F=(x-8z)i+(x+9y+z)j+(x-8y)k find the curl of F

Homework Equations

curl of F= del X F

The Attempt at a Solution

1. First I took the partial with respect to y of (x-8y) and subtracted the partial with respect to z of (x+9y+z). From this I got (-8-1) Then I took the partial with respect to x of (x-8y) and subtracted the partial with respect to z of (x-8z), getting (1+8). I then took the partial with respect to x of (x+9y+z) and subtracted the partial with respect to y of (x-8z), getting (1-0). So I took (-8-1)-(1+8)+(1-0) and got an answer of 1, but this was wrong.

Homework Statement

2.F=(7e^x)i-(14e^y)j+(7e^z)k find the curl of F

Homework Equations

curl of F= del X F

The Attempt at a Solution

2. For this, since I was always going to be taking the partial with respect to a variable that was not in that part of the function, everything would be zero. Ex: partial with respect to x of -14e^y should be zero I believe

 

[grzz]

For the curl of the first function I think that in finding the jth component of curlF you have to take the partial wrt z of (x-8z) and subtract from this the partial wrt x of (x-8y) but you did the reverse.

Note also that curl F is a vector and so it must remain as i(...) +j(...) +k(...).

 

[grzz]

Yes the curl of the second function F gives the zero vector.

 

[hallnate]

Yes the curl of the second function F gives the zero vector.

I thought so. I entered this in and it was wrong. I'll just try emailing my professor.