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avatar+105 


Watching videos on khan academy..hard to follow his length of a vector video. so need a bit of help here. 

u= (1, 2, 3) v= (-2, 0, 1) 

Find the legnth of u & v

i got ||u||= √1²+2²+3² =3.741
       ||v|| = -√2²+0²+1² = -2.236

3.741+ -2.236 = ||u v|| = 1.51

am i doing this right? 

 Jun 18, 2014

Best Answer 

 #3
avatar+105 
+5

Thank you both!! 

 Jun 18, 2014
 #1
avatar+33654 
+5

Length of v is √( (-2)2 + 02 + 12) = √(4+0+1) = √5 

5=2.2360679774997897

If the last part is meant to be the length of the vector sum of u and v, then you have to sum the components first, before calculating the length, not add the lengths of the individual vectors together.

u+v = (-1, 2, 4)

length of u+v = √( (-1)2 + 22 + 42) = √21

21=4.58257569495584

 Jun 18, 2014
 #2
avatar+26396 
+6

u= (1, 2, 3)    

v= (-2, 0, 1) 

w=u+v=(123)+(201)=(122+03+1)=(124)

 

w=(1)2+22+42=1+4+16=214.58257569496

 Jun 18, 2014
 #3
avatar+105 
+5
Best Answer

Thank you both!! 

Strider Jun 18, 2014

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