Cross product 1

[akipina]

MUCH easier than the right foot rule. That was just ridiculous.

[sopro671]

Thanks really helped alot

[xXSabzzXx]

Great video thanks.

But I've been taught to use some sort of screw rule instead of the right hand rule... Seems a bit easier. For those who dont know how to use the right hand rule this might help. imagine turning a screw/screwdriver from a to b.. You are turning it clockwise and when you do that, the screw moves forwards so the vector is in that direction. But when you move it from b to a. It is anticlockwise and the screw moves outwards. So the vector is out of the page.

[Elzelgator]

awesome

[narutosramenbuddy]

i enjoyed the bonus lesson on arrows.

[chickenhuntaz]

if "n" points into the page. wouldn't the arrow be pointing up in your 3d diagram?

[flyhalfinoz]

thank you!! u saved me from an eternal confusion of the scalar/vector product!!

[ELECTRIC67100]

khan as excellent as always in his explanation

[musicandmeareinlove]

how do we find the angle between two vectors?

[xxilikemustardxx]

@musicandmeareinlove did you ever find this out? if so, tell me :D

[musicandmeareinlove]

@xxilikemustardxx yep i did

let A and B be two vectors

A=xi + yj + zk

and B= ai + bj + ck

now, A*B =A B sin (theeta) n (n gives the direction)

find the magnitude of A*B using the matrix method and equate it to A B sin (theeta)

you'll get the value of sin (theeta) then look uo in the log table and u'll get the vlue of theeta...

[RJonStreetz]

@musicandmeareinlove Angle?? What do you mean? Just use a protractor. Or am I missing something??

[musicandmeareinlove]

@RJonStreetz lol...wt if u're just given the coordinates...? in d form A=xi + yj + zk

and B= ai + bj + ck and asked to find the angle betn them? u cant always draw the vectors on d cartesian plane and measure the angle between em...

[RJonStreetz]

@musicandmeareinlove Oh yeah right...forgot about that....Thanks!

[musicandmeareinlove]

@RJonStreetz  :)

[anisotropicentity]

reminded me of flemings right hand rule (:

[nico2panama]

You can also take the cross product in seven dimensions. just in case :)

[TheFutureIsRightHere]

I still didn't get the "Right hand rule" :p

[anuragsahoo94]

why sine?

[gaypotter]

u are great at teaching, thanks!

[divvy1400yam600]

There is no doubt whatsoever that your videos are informative.

But my word ...do you over elaborate. !

[92syakeer]

thanks for the video. excellent explanation of in and out of the page! dont worry, we got it :)

[wingmanbros]

i love your lessons

[onetimeuse12]

isn't the formula used with cos?

[Rand0mAsian]

@onetimeuse12 thats the dot product =)

[13000000a]

wait....so if i have b x a instead of a x b the 25 would be a vector outta the page?

[memirandawong]

.....this concept sounded mysterious and difficult until I watched this video...

[bigmosofly]

you just saved me from failing my statics test. thank you!!!

[nilatstc]

I didn't quite get the cross product for the past 7 years and I managed to understand it in just 10 mins of this video.... Great job!

[beastlt12]

Excellent. Exactly what I was looking for.

[VulcanSpirit]

dude fyi that is a pro hand :)

[kmiller1985]

By far the easiest version of the right hand rule I have seen.

[lseateal]

wat if i dont have any fingers?

[paskavatta]

try to get some helping hand then.

[ichinarukurumaki]

@lseateal use somebody elses

[lseateal]

@ichinarukurumaki

but im not allowed to use touch or talk to the people around me during a test! and i cant bring a friend in with me... i guess im destined to fail at any exam with cross products... : (

[nico2panama]

@lseateal put on gloves.

[bartcase]

@lseateal then how did you type this comment?

[hashmat187]

@lseateal how did you type this comment then

[KimJong7hrill]

@lseateal

lol I don't have any fingers either.

[DasGewitter83]

@lseateal I guess it is not very difficult to imagine it

[SuperThegreat007]

@lseateal you should imagine fingers and then work with it

[lastshadowmonkeys]

Thanks so much! Great help this :D

[TheMrHandyMan]

I posted a quick example of how Cross Products are used in engineering. Hope you enjoy! Thanks for your videos Sal,

[jjdc1]

thank you, you have the best video that explains what a product rule is.

[ose90]

very lucid explanation, thanks!

[Ren520]

that was very concise..

i'm learning this prior to my fall class because im afraid it'll be too difficult.

im sure i'll do great with your vids, in addition to MIT's OCW.

by the way,

you achieved and did so many great things in life,

congrats!

[hylianloach]

Alternate method is to find the determinant - assume vector x = (a,b,c)T, y = (d,e,f)T, then the cross product of x and y is the determinant of the 3x3 matrix:

i j k

a b c

d e f

Obviously the cross is given by (i,j,k)T

[crashonthehumble]

outstanding

[SteveTheCart]

Wow!

[cuzoma7]

Thank you so much. This was extremely helpful. Especially the right hand rule. God bless you. =)

[Eastyles]

Thank you for all of these videos.

[Barnekkid]

That was very clear, especially the part about the right hand rule.

[brco2003]

You should give yourself more credit with your artistic abilities; your work is really good.

[GoldAK47]

woohoo! First view, first comment!

This will help me in vectors since this is one of the stuff I will have to learn next year. Thanks a lot