SOLUTION: Hello, I have several problems which I attempted. However, I dont understand why one is vector and the other scalar. Use the vectos u=<2,2> and v=<-3,4> to find the indicated qu

Algebra ->  Trigonometry-basics -> SOLUTION: Hello, I have several problems which I attempted. However, I dont understand why one is vector and the other scalar. Use the vectos u=<2,2> and v=<-3,4> to find the indicated qu      Log On


   

Question 118423: Hello, I have several problems which I attempted. However, I dont understand why one is vector and the other scalar.
Use the vectos u=<2,2> and v=<-3,4> to find the indicated quantity. State whether the result is a vector or a scalar.
1) u X u
2) (u X v)v I got <-6,8> vector
The first one says that it is 2 sq.root 2 squared, which is 8, and scalar.
Why? What is the difference?
Big thank you to who explains this. You people are amazing, and thank you for your time.

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
I'm not sure what you want to do here. Does the "X" mean dot product (it cannot be the cross product)?

Remember the dot product is defined as:



So is...

Use the definition of the dot product



Plug in the entries of




Multiply

Add


Notice how the answer is a single value. So it is a scalar.


Now if you want to find the length of , simply take the square root of the answer to get




But once again, I'm only assuming that's what you want since I don't know what the "X" stands for.




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2)

Once again I don't know what the "X" stands for. So please let me know what this operator stands for.