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anonymous
 one year ago
Can someone help me with some math questions? I'll fan and medal. :)
anonymous
 one year ago
Can someone help me with some math questions? I'll fan and medal. :)

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hartnn
 one year ago
Best ResponseYou've already chosen the best response.1do you know how to get projection of one vector on other? tried to solve this?

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1Projection of vector a on vector b is \(\LARGE \dfrac{a.b}{b}\)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So it would start off like this?.... (1.6i + 3.3j) (2.1i 0.5j) = 3.36 6.93 1.65 0.8

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1note that \(i . j \) and \(j.i\) both = 0 as they are perpendicular vectors!

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1so you'll only have 1.6*(2.1) + 3.3*(0.5) = ...

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So just to be clear  Whenever you're multiplying the different variables in a vector, the become zero?

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1correction* whenever you're taking the dot product of perpendicular vectors, the product = 0 i , j and k are perpendicular vecotrs

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Got it. So... 1.6*(2.1) + 3.3*(0.5) = 3.36i 1.65j then you divide that answer by (2.1i 0.5j) (3.36i 1.65j) / (2.1i 0.5j) =...

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Give me just a second on the division. I think I did something wrong.

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1so your u.v will be = 1.6*(2.1) + 3.3*(0.5) = ... its a numeric value, because its a dot product it won't have i's and j's in it!

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1and for the denominator its magnitude of v = \(\sqrt {2.1^2+0.5^2} = .. \) there is no need of doing complex divisions :)

hartnn
 one year ago
Best ResponseYou've already chosen the best response.11.6*(2.1) + 3.3*(0.5) = 5.01

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So the numerator is 5.01 and the denominator is about 2.16 and you would divide that?

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1thats right that will give you the magnitude of the projection vector :)

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1thats the magnitude, now you only need the direction of projection vector and since projection is along the vector 'v' its direction will be same as that of vector v !

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1for that, you'll need to find the unit vector in the direction of v and then mutiply the above answer to it.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Wouldn't "b" be the direction? (2.1i 0.5j)

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1you need projection of vector u along vector 'v' so its direction will be along vector 'v' whats b and where it came form ?

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1unit vector along v = v/ v and we already know v = 2.16

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1so unit vector along v = (2.1i 0.5j)/ 2.16 and your projection will be 2.32 times the above answer

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0(2.1i 0.5j)/ 2.16 Would that be (0.97i 0.23)?

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1what do u get after multiplying that with 2.32?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.02.32 (0.97i 0.23) = (2.25i 0.53j)

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1two negatives become positive! and you can approximate 2.25 to 2.3 and 0.53 to 0.5 :)

hartnn
 one year ago
Best ResponseYou've already chosen the best response.12.32 * 0.97 = +2.3 2.32 * 0.23 = +0.5

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Oops! I didn't even see the double negatives. Thank you for catching that. So the answer would be B. (2.3i +0.5j)

hartnn
 one year ago
Best ResponseYou've already chosen the best response.1yes, correct! good work :)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Thank you for your help. :)
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