# MATHS: Vectors (intermediate)

Whats the difference between a right/left handed set of vectors.

My text book explains it too poorly to understand and my teacher ordered my to use the text book to find out.

I tried to use google to find an answer but all websites I went to talk about right/left handed vector sets assuming you know how to differentiate between them.

Thanks!

I remember left and right-vectors vaguely. I think (if I’m remembering correctly) that left-handed vectors have to do with holding up your left hand at eye level with you index finger pointing up and your thumb pointing to the right… In any case, I’m not sure exactly what you’re trying to understand about vectors, but perhaps these websites will help you out:

I hope these help.

Edit:

Yes, here is another link for differentiating between left and right vectors. For right-handed vectors (using your right hand), treat your index finger as the y-axis and your thumb as the x-axis. The z-axis goes away from you. Use the same method for left-hand vectors, only using your left-hand. Does this help at all?

from that link, apparently left handed has x in one direction, while right handed has x in the other. all i ever remember is the right hand rule for cross products, which means you align your index finger to one vector, your thumb to the other, and your palm points to the cross product vector.

i should hope that you shouldnt have to worry about which system they are, so long as you apply the same rules to all of them, it should work out. in all of my classes with vectors, we’ve never once mentioned a “left handed” system, from calculus to electrical engineering to computer graphics. always right hand rule.

Originally posted by EFloUVA
In any case, I’m not sure exactly what you’re trying to understand about vectors …
I have an exercise where you are given three vectors in column form and you have to state whether or not they represent a right handed or left handed set. The vectors aren’t drawn.

I know you can tell if the are right or left handed set by looking at the sign of the scalar triple product, but i was wondering how to tell using ur fingers + intuition.

Originally posted by ckin2001
i should hope that you shouldnt have to worry about which system they are, so long as you apply the same rules to all of them, it should work out. in all of my classes with vectors, we’ve never once mentioned a “left handed” system, from calculus to electrical engineering to computer graphics. always right hand rule.
This is sixth form a-level further maths (if you’re familiar with the english education system) and it isnt really a big deal (Half a page in my text book)

Were ur “classes with vectors” at university for an engineering course / computer course or at school like me? Im thinking of studying engineering at university, so if so, how much maths is involved and what areas of maths do u do?

i studied them in my intro to ECE class for flux/current relations. they came up in all 4 required physics courses. and in linear algebra. and…um…now in computer graphics. both the mathematical type, and the storage container programming type.

doesnt the scalar triple product also signify the volume of a polygon made up of the 3 vectors? doh, the absolute value does that…

mmm wikipedia

The coordinate system i, j, k is called right handed, if the three vectors are situated like the thumb, index finger and middle finger (pointing straight up from your palm) of your right hand. Graphically the cross product can be represented by