What is the purpose of the dot product as opposed to the purpose of the cross product?

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- Apr 17th 2012, 05:03 PMdelgeezeedot vs. cross
What is the purpose of the dot product as opposed to the purpose of the cross product?

- Apr 17th 2012, 05:17 PMskeeterRe: dot vs. cross
the result of a dot product of two vectors is a scalar ...

work, a scalar quantity of energy, is the dot product of force and displacement vectors

$\displaystyle W = \vec{F} \cdot \vec{\Delta x}$

the result of a cross product of two vectors is another vector ...

torque, a vector quantity, is the cross product of radius and force vectors

$\displaystyle \vec{\tau} = \vec{r} \times \vec{F}$

try a google search ... you'll find many more examples and applications. - Apr 17th 2012, 05:43 PMPlatoRe: dot vs. cross