Question

Vectors. Please help!!!!!

Answer 1

Study, check out what I said in the chat.

Answer 2

Hrm? You should type up the entire question then.

Answer 3

Yes what is the question?

Answer 4

\(\ \ \huge What does this mean: \vec{u}_{\vec{w}} \).
@kevo I'm in precalc. Not doing derivative stuff.

Answer 5

Im given that vector v is (3,2) and w is (-2,5)

Answer 6

@KingGeorge Vector Help!

Answer 7

Have you learned in class about the dot product? Or what is the name of the section of the book where this question is found?

Answer 8

Yes, we learned about the dot product and orthogonal today

Answer 9

What should I do now? How am I supposed to solve this?

Answer 10

Anyone?

Answer 11

are you multiplying the vectors?
looks like vector subscript vector which is crazy

Answer 12

I'm not actually sure what that notation means, but for now, I'll work off of the assumption that it represents vector projection.

Answer 13

If it helps, I can post the WS that I am working on here...

Answer 14

So you want to find the the projection of \(\vec u\) on \(\vec v\). To do this, there's a simply formula.\[\large \vec u_{\vec v}= {\vec u \cdot \vec v \over |v|^2}\;\; \vec v\]

Answer 15

If you could post the worksheet, that might be helpful to give us an idea of what the notation probably means.

Answer 16

If you want to find the dot product you have <3,2><-2,5>=(3)(-2)+(2)(5)=-6+10=4

Answer 17

Vector subtraction!!! LOL You simply subtract the components LOL <3-2,-2-5>=<1,-7>

Answer 18

Yes for that first one... But 3/4 are where Im confused

Answer 19

oh i just realized u is not a given vector, prob represents unit vector

find unit vector of w

Answer 20

Here's one with better quality

Answer 21

Unit vector?

Answer 22

I agree with dumbcow. That would make much more sense.

Answer 23

Yes the unit vector!!! LOL You want to find a vector in the direction of the vector v with length 1 and you want to find a vector in the direction of w with length 1.

Answer 24

? How do I do that?

Answer 25

To find the unit vector of some vector \(\vec a\) use the following.\[{\vec a \over |\vec a|}\]where \(|\vec a|\) is the length of the vector.

Answer 26

You simply divide the given vector by its length. You know how to find the length of a vector?

Answer 27

Length of a given vector. Example: Vector v=<3,4>. Call u the unit vector in the direction of v. Then u= <3,4>/ sqrt(3^2 + 4^2)=<3,4>/sqrt(9+16)=<3,4>/5=<3/5,4/5> final answer is u=<3/5,4/5>

Answer 28

So the length of a vector v=<a,b> is given by sqrt(a^2 + b^2)

Answer 29

Okay I have another question.... So is the dot product the same as ? What's the difference? When do you use either