Use the dot product to determine which of the following vector pairs are orthogonal.
a. v1 = (-5,5) and v2 = (1,1)
b. v1 = (154,169.4) and v2 = (88,64)

Question

Use the dot product to determine which of the following vector pairs are orthogonal.
a. v1 = (-5,5) and v2 = (1,1)
b. v1 = (154,169.4) and v2 = (88,64)

yanasidlinskiy · Answer

The dot product of the first vector pair is -5*1+5*1=0 so these two vectors are orthogonal

anonymous · Answer

so that will be be answer for a?

yanasidlinskiy · Answer

yes....does that make sense?

anonymous · Answer

yes. but what about b?

yanasidlinskiy · Answer

hmm.... I'll let @kc_kennylau answer that one:)

kc_kennylau · Answer

Well, the dot product isn't zero, so they aren't orthogonal.

anonymous · Answer

im confused...

ipwnbunnies · Answer

Right, when you dot product two vectors and they're equal to 0, that means the vectors are orthoganal.

yanasidlinskiy · Answer

OMG>_< lol........... @kc_kennylau what did you do...that made her so confused...jk....lol..

yanasidlinskiy · Answer

@tkhunny .....help...

ipwnbunnies · Answer

I thought we already answered them? Lol.

yanasidlinskiy · Answer

lol.......she wants to know b also....

ipwnbunnies · Answer

For Part B, all the components of the vectors are positive.
Therefore, when you dot product them, you cannot possibly get 0.
Therefore, they cannot be orthogonal.

tkhunny · Answer

Calculate the dot product.  If you get zero (0), the are orthogonal.  If you do not get zero, they are not orthogonal.  Stop being confused.

yanasidlinskiy · Answer

@tkhunny ......Well at least somebody knows how to figure this out!.....Simple and easy!!!

tkhunny · Answer

Let's not take that attitude when this is the third time the exact same thing has been written.

ipwnbunnies · Answer

Lel.