Thread: vector question

Show that the magnitude of a vector u is equal to (u x u)^1/2



If a x b = a x c, does a = b? Justify your answer.

Show that the magnitude of a vector u is equal to (u x u)^1/2

I think you mean the square root of the dot product rather than the cross product ...

If a x b = a x c, does a = b? Justify your answer.

are you sure the statement isn't
"If a x b = a x c, does b = c ?"

Originally Posted by blague

Show that the magnitude of a vector u is equal to (u x u)^1/2

Mr F says: Apply the basic definition of the dot (scalar) product to u.u ....

If a x b = a x c, does a = b? Justify your answer.

Mr F says: a x b = a x c => a x b - a x c = 0 => a x (b - c) = 0 .....

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