# Homework Help: Vector Field

1. Jan 16, 2012

### sandy.bridge

1. The problem statement, all variables and given/known data
Let
$$\vec{F}=(1/(x+2), 1, y)$$.
The field line that passes through (2, 3, 1) also passes through the point (3, y, z).
What is tan(y+2z)?
Let $$\vec{r}_1=(2, 3, 1), \vec{r}_2=(3, y, z)$$
Since the field line passes through both points, we have
$$\vec{F}(2, 3, 1)//(\vec{r}_2-\vec{r}_1)$$
hence when cross multiplied, it should equal zero!
However, I am not getting the right answer using this approach. Can someone pinpoint where I perhaps have made an error?
Thanks!

Last edited: Jan 16, 2012