Question 118423
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:

*[Tex \LARGE \v{a}\bullet\v{b}=a_0*a_0+b_1*b_1] 



So *[Tex \LARGE \v{u}\bullet\v{u}] is...


*[Tex \LARGE \v{u}\bullet\v{u}=u_0*u_0+u_1*u_1] Use the definition of the dot product




*[Tex \LARGE \v{u}\bullet\v{u}=2*2+2*2] Plug in the entries of *[Tex \Large \v{u}]





*[Tex \LARGE \v{u}\bullet\v{u}=4+4] Multiply


*[Tex \LARGE \v{u}\bullet\v{u}=8] Add



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



Now if you want to find the length of *[Tex \Large \v{u}], simply take the square root of the answer to get


*[Tex \LARGE sqrt{8}=2sqrt{2}]



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.