Vector - sum of two vectors * some const

In summary, the conversation discusses finding the solution to a system of equations involving a vector. The vector <2, 3> is stated to be the sum of two other vectors, <3, 2> and the orthoginal vector <-2, 3>. The system of equations is set up as 2x + 3y = 13 and 2x - 3y = 0, and the solution is found using gaussian elimination. However, there is some confusion as to whether the solution is correct or not.
  • #1
asdfmaster
3
0
a*<3, 2> + b*<-2, 3> = <2, 3> - A, B?

Homework Statement


There exists a vector <2, 3>.
Said vector is the sum of two other vectors <3, 2> and the orthoginal to <3,2> (which I think is <-2, 3> right?)


Homework Equations


<2, 3> = a<3, 2> + b<-2, 3> where a, b are constants


The Attempt at a Solution


I tried solving the x and y seperately: 2 = a*3 + b*-2 but there's many ways this can be done, none of which held true also for the y.
 
Last edited:
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  • #2
Maybe I didn't describe it well enough. The problem is that I have a vector <2, 3> and I must get from the origin to (2, 3). I start moving parallel to <3, 2> and make a right angle turn. Where do I make the right angle turn?
 
  • #3
EDIT:
I take back the above matrix, which I am now deleting. The system you'll need to solve is

[tex]
\begin{align*}
2x + 3y &= 13\\
2x - 3y &= 0
\end{align*}
[/tex]

Which can be solved via elimination.
 
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  • #4
Well, I just tried elimination using gaussian elimination

Code:
Starting matrix:
2  3    13
2 -3    0

to
2  3    13
0 -6   13

to
1  3/2    13/2
0  1      13/-6

to
1  0    39/4
0  1    13/-6

so I end up with x = 39/4 and y=13/-6
But I asked and he told me that it wasn't correct.
 
  • #5
asdfmaster said:
Well, I just tried elimination using gaussian elimination

Code:
Starting matrix:
2  3    13
2 -3    0

to
2  3    13
0 -6   13

to
1  3/2    13/2
0  1      13/-6

to
1  0    39/4
0  1    13/-6

so I end up with x = 39/4 and y=13/-6
But I asked and he told me that it wasn't correct.

Has he given you the correct answer? Maybe I don't understand the question completely.
 

FAQ: Vector - sum of two vectors * some const

1. What is a vector and how is it different from a scalar?

A vector is a mathematical quantity that has both magnitude and direction. This is different from a scalar, which only has magnitude and no direction.

2. How do you calculate the sum of two vectors multiplied by a constant?

To calculate the sum of two vectors multiplied by a constant, you first need to multiply each vector by the constant. Then, add the resulting vectors together to get the final sum vector.

3. Can the sum of two vectors multiplied by a constant be negative?

Yes, the sum of two vectors multiplied by a constant can be negative. This will depend on the direction and magnitude of the individual vectors, as well as the constant used.

4. What is the significance of multiplying vectors by a constant?

Multiplying vectors by a constant allows us to scale the vectors, making them longer or shorter. This can be useful in many applications, such as scaling forces or velocities in physics.

5. Can the sum of two vectors multiplied by a constant be larger than the original vectors?

Yes, the sum of two vectors multiplied by a constant can be larger than the original vectors. This will depend on the magnitude and direction of the individual vectors, as well as the constant used.

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