1. ## Line Integral Help

Can anyone explain to me why the image is true?

2. ## Re: Line Integral Help

Originally Posted by aprilcm
Can anyone explain to me why the image is true?
Note: This is only true if B is not a function of s!

$\displaystyle \int_C \dfrac{\vec{B} \cdot \vec{B}}{B}~ds = \int_C \dfrac{B^2}{B}~ds = \int_C B~ds = B \int_C ds$

-Dan

3. ## Re: Line Integral Help

Note that the vector $\vec{B}$ (or B) might depend upon s as long as B (the magnitude of $\vec{B}$) does not.