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anonymous
 5 years ago
let a and b two vectors such that vector a = 3i + 4j, and the magnitude of vector b = 4, where the angle between the given vectors is 60*. If the vector (m(vector a)+vector b) is perpendicular to vector b, find the value of m.
anonymous
 5 years ago
let a and b two vectors such that vector a = 3i + 4j, and the magnitude of vector b = 4, where the angle between the given vectors is 60*. If the vector (m(vector a)+vector b) is perpendicular to vector b, find the value of m.

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amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0I get it up to the point m(vector a) is m a scalar then?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0we can just say that Bv is <0,4> right? thats a vecotr of magnitude 4 :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0no we cant, we have to base it off of A... and 60 degree from it.... back to the draing pad :)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i found that (vector a) dot (vector b)= 10

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0by process of the math? or looking at the answers :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0can you type it out so I can see it :) that way I know what we both are looking at.... get me up to speed.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0cos 60= 1/2 1/2= ((vector a) dot (vector b))/(magnitude of vector a * magnitude of vector b) 1/2= ((vector a) dot (vector b))/4*5 1/2= ((vector a) dot (vector b))/20 ((vector a) dot (vector b)) = 10

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0to keep things clean; we can use a to mean vector a and b likewise. magnitude is a works good. cos(60) = 1/2 1/2 = a*b / a b 1/2 = a*b / 4*5 1/2 = a*b /20 a*b = 10 ..good work :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0vectors that are perpendicular have a dot product of zero.

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0do we know what the vector parts for b are? I was working on that :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0we can figure it out :) do we need to?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0heres what I got from what we know.

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0b has 2 options up and to the left, or down and to the right.

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0the original angle of "a" is tan1(4/3) = 53.1301

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0b has an angle of either 6.8699 or b has an angle of 113.1301

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.04sin(t) will give us the y value and 4cos(t) will give us the x values right?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0the left vector option is <1.57128, 3.67846> for "b" that gives us an angle betwwen them of 60 and a magnitude of 4

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0the other option for b is <3.97128, .47846>

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0since we cant move a :) we need to work with these 2 possibilities and see what we get :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0Do you know if we should include the m in the vector like this? <m3, m4> + < x , y > "b1"  <m3 1.57128, m4 +3.67846>

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0ok i think i can take it from here

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0itd a been nice if they had given us a pretty angle to work with off of "a" lol

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yeah i know, vector is very difficult to deal with

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0if you got it from here....good luck :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0you can pick whichever vector for b gets you that 10 ;)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0thank you very much for your help
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