- #1
ThomasMagnus
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Homework Statement
I have been doing dot and cross product recently. I get how to calculate everything; however, I am confused about which angle to use when asked to find the angle between two vectors. When you use the cross product, you always end up with 2 answers, for example 120° and 60°. However, if you were to find the angle between them using dot product, you would only get one unique answer, as cos 120 and cos 60 are the opposite sign. So my question is, when asked to find the angle between two vectors given in i j k notation, is it best to always do it using dot product to avoid this confusion?
Also, is it correct to say that the angle found between vectors using the dot product MUST be the same as when using the cross product method?
Homework Equations
[itex]\vec{a}[/itex][itex]\bullet[/itex][itex]\vec{b}[/itex]=|a||b| cos [itex]\theta[/itex]
[itex]\vec{a}[/itex] [itex]\times[/itex] [itex]\vec{b}[/itex]=|a||b| sin [itex]\theta[/itex]
The Attempt at a Solution
N/A
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