Yes, my major strikes again, ive spent 2 hours on this problem, all of my work makes sense yet the online homework system doesnt like my answer

For the following three vectors, what is -2.00 C o (-5.00 A x B ) The "o" means a dot product and the "x" is a vector product


A = 2.00i + 3.00j - 4.00k
B = -3.00i + 4.00j + 2.00k
C = 7.00i - 8.00k

good luck, it needs to be 3 significant figures, and you cant do something like 400., because believe me ive tried.

For anyone kind enough to attempt this for me, please just don't give the answer, I'm just as interested in how you obtained the work/answer so I can do well on the test

Thanks

I will tell you if you give me a good geometric sense for what a quotient space is.

okay. first off you are forced to use the basis (i, j, k) because you are already given vectors in that basis.

A = [2.00, 3.00, -4.00]
B = [-3.00, +4.00, +2.00]
C = [7.00, 0, -8.00]

The rest proceeds normally. Sorry to give you answers, but there's not a lot of content here.

You end up with AxB = [22.0, 8.00, 17.0]
-5 * AxB = [-110, -40.0, -85.0] (*cross product is compatible with scaling)
C o (-5.00 * AxB) = -90.0 (*dot product is bilinear)
-2.00 * -90.0 = 180.

Edit: Not sure what you mean by "can't do something like 400" because that has exactly 3 significant figures. Try 1.8e2 I guess?

it was 900. the program is dumb

if it's 900 then:

1.) i, j, k are given and not linearly independent, or
2.) the program is wrong.

Or dumb...

irony masterstroke

You just forgot to save the JKL. Oh, what? Nevermind.

=[ i got the answer and you guys still make me feel dumb =[ /wrist /WRIST