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Explain how i and j notation works please?

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Reply 20

Zacken

Original post by Vikingninja

The hats are for in the direction. Without the hats is for the position as in for a location.

I don't see how this makes sense. The hats are for unit vector. Not for in the direction.

Reply 21

Vikingninja

Original post by Zacken

I don't see how this makes sense. The hats are for unit vector. Not for in the direction.

As in the vector in that direction. e.g. 6i^ has a length of 6 in the x direction. As far as I'm aware without the hat is the position of a graph, e.g. 6i on a graph is at 6 on the x direction

(edited 8 years ago)

Reply 22

Zacken

Original post by Vikingninja

As in the vector in that direction. e.g. 6i has a length of 6 in the x direction.

Yeah, I know. I was questioning the use of

6\hat{i}

v/s

6i

Reply 23

Vikingninja

Original post by Zacken

Yeah, I know. I was questioning the use of

6\hat{i}

v/s

6i

Just edited the second part afterwards. With no hat its not a vector but a position. Some questions will give two points with i, j and k and you need to work out the vector between them.

(edited 8 years ago)

Reply 24

Zacken

Original post by Vikingninja

As in the vector in that direction. e.g. 6i^ has a length of 6 in the x direction.

this

and

As far as I'm aware without the hat is the position of a graph, e.g. 6i on a graph is at 6 on the x direction

this

are the exact same things.

Reply 25

Vikingninja

Original post by Zacken

this

and this

are the exact same things.

What I mean with the hat is that its a vector/length in that direction, without the hat its a position and does not create a length along that direction. Between two points the vector would have hats as its a length.

With my example of without the hats its at a position of 6 in the x direction and would be 6 from the origin if it were a unit vector.

Reply 26

Zacken

Original post by Vikingninja

Draw the position vector

6i

. It's an arrow starting from the origin and extends upwards 6 units.

Reply 27

Vikingninja

Original post by Zacken

Draw the position vector

6i

. It's an arrow starting from the origin and extends upwards 6 units.

Oh right then, I'll need to read up my vectors then.

Reply 28

username1560589

Original post by Zacken

Draw the position vector

6i

. It's an arrow starting from the origin and extends upwards 6 units.

With standard orientation of the axes it extends right, not upwards.

Reply 29

Zacken

Original post by morgan8002

With standard orientation of the axes it extends right, not upwards.

I was thinking of complex numbers. :rofl:

Reply 30

username1560589

Original post by Zacken

I was thinking of complex numbers. :rofl:

Another reason I prefer the hat version.

Reply 31

Zacken

Original post by morgan8002

Another reason I prefer the hat version.

Good point...

Reply 32

rayquaza17

Original post by morgan8002

Another reason I prefer the hat version.

I like hats, but not i,j,k.
It's all about

\hat{e}_1

, etc.

(I'm currently doing some work on suffix notation and using the numbers rather than x,y,z or i,j,k makes things a lot easier later on down the line :colondollar:

)

Reply 33

drandy76

Original post by rayquaza17

I like hats, but not i,j,k.
It's all about

\hat{e}_1

, etc.

(I'm currently doing some work on suffix notation and using the numbers rather than x,y,z or i,j,k makes things a lot easier later on down the line :colondollar:

)

Had some notes using e^i and a few months later I have no clue what I was on about

Posted from TSR Mobile

Reply 34

rayquaza17

Original post by drandy76

Had some notes using e^i and a few months later I have no clue what I was on about

Posted from TSR Mobile

e^i

e_i

? Two very different things!

Reply 35

drandy76

Original post by rayquaza17

e^i

e_i

? Two very different things!

The latter

Posted from TSR Mobile

Reply 36

Zacken

Original post by drandy76

The latter

Posted from TSR Mobile

Orthogonal vectors that form a orthonormal basis. :yep:

(from what little I know, somebody jump in and correct me! :tongue:

)

Reply 37

drandy76

Original post by Zacken

Orthogonal vectors that form a orthonormal basis. :yep:

(from what little I know, somebody jump in and correct me! :tongue:

)

From what I recall they're components? I'll check tomorrow and get back to you but I recall reading about them to show why vector addition works

Posted from TSR Mobile

Reply 38

rayquaza17

Original post by drandy76

From what I recall they're components? I'll check tomorrow and get back to you but I recall reading about them to show why vector addition works

Posted from TSR Mobile

Yeah like e_1 is the same as x. It's just a different way of writing it. (No latex as I'm on my phone, sorry)