Operations on vectors

• A

• B

• C

• D

What are all the possible formulae for the scalar product of two vectors?

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Find the dot product if u=<3,9> and v=<6,5>

• 69
• 63
• 57
• -27

4w*-3u

• -1680

• 1200

• -1200

• 1680

The cross-product can be used in both two and three dimensions

• I agree

• I disagree

• It depends

• Not sure

The magnitude of the vector product is __________.

• 0

• 1

• 2

• 3

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Let:

 $\overrightarrow{a}=-3x\overrightarrow{\ i}+x\overrightarrow{\ j}-4\ \overrightarrow{k}$ 
 $\overrightarrow{b}=2\overrightarrow{\ i}+4\overrightarrow{\ j}+5\ \overrightarrow{k}$  

 $\overrightarrow{c}=-3\overrightarrow{\ i}+2\overrightarrow{\ j}+\ \overrightarrow{k}$  
If  $\overrightarrow{a}\ \perp\ \overrightarrow{b}$  then $\overrightarrow{a}-\overrightarrow{c}=$  

•  $-33\overrightarrow{i}-8\overrightarrow{j}-50\overrightarrow{k}$  

•  $-27\overrightarrow{i}-8\overrightarrow{j}-5\overrightarrow{k}$  

•  $-27\overrightarrow{i}-12\overrightarrow{j}-5\overrightarrow{k}$  

•  $33\overrightarrow{i}-12\overrightarrow{j}-5\overrightarrow{k}$  

•  $-33\overrightarrow{i}-12\overrightarrow{j}-5\overrightarrow{k}$  

 $i\times\left(\overrightarrow{\ a\ }\times i\right)+j\times\left(\overrightarrow{\ a\ }\times j\right)+k\times\left(\overrightarrow{\ a\ }\times k\right)=$  

• 0

•  $\overrightarrow{\ a\ }$  

•  $2\overrightarrow{\ a\ }$  

• 3

What is the sum of squares of the direction cosines

• 1

• r²

• 0

• None of the above