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What is the cross product of #<9,2,8 ># and #<1,3,-4 >#?

Answer 1

Leo Abeyta

The vector is #=〈-32,44,25〉#

A vector perpendicular to two other vectors is the cross product.

#| (veci,vecj,veck), (d,e,f), (g,h,i) | #

where #〈d,e,f〉# and #〈g,h,i〉# are the 2 vectors

Here, we have #veca=〈9,2,8〉# and #vecb=〈1,3,-4〉#

Consequently,

#| (veci,vecj,veck), (9,2,8), (1,3,-4) | #

#=veci| (2,8), (3,-4) | -vecj| (9,8), (1,-4) | +veck| (9,2), (1,3) | #

#=veci(-2*4-3*8)-vecj(-9*4-8*1)+veck(9*3-2*1)#

#=〈-32,44,25〉=vecc#

Verification using the two dot method

#〈-32,44,25〉.〈9,2,8〉=-32*9+44*2+25*8=0#

#〈-32,44,25〉.〈1,3,-4〉=-32*1+44*3-4*25=0#

So,

#vecc# is perpendicular to #veca# and #vecb#

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Answer 2

Isabella Alvarez

The cross product of <9,2,8> and <1,3,-4> is <32, 76, 25>.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

What is the cross product of #&lt;9,2,8 &gt;# and #&lt;1,3,-4 &gt;#?

What is the cross product of #<9,2,8 ># and #<1,3,-4 >#?