vector

[newton1]

i know A.B = AB cos(x), and AxB = AB sin(x) ...
but if we face the problem didn't told us what should we use
then how to know what should we use
how to different scalar product or vector product.....??

[HallsofIvy]

Understanding the problem might help!


It might be an important point that "AxB = AB sin(x)" is not true.
AxB is a vector whose length is the length of A times the length of B times sin(x). If you made a little more effort to distinguish between vectors and their lengths in your writing, it might help to decide whether the product in your problem was to result in a vector or a scalar![:)]