Cosine of Vector: Adjacent/Hypothenuse

  • Thread starter Thread starter Tiven white
  • Start date Start date
  • Tags Tags
    Cosine Vector
AI Thread Summary
The discussion centers on the incorrect assertion that "the cosine of a vector is equal to the opposite over its magnitude." Participants clarify that cosine is defined for angles, not vectors, and emphasize that the term "opposite" is improperly used in this context. The correct interpretation is that cosine relates to the ratio of the adjacent side to the hypotenuse in a right triangle, not to vector components. Additionally, the statement regarding the cosine representing the y component of a vector over its magnitude is also deemed false. Overall, the conversation highlights misunderstandings about the definition and application of cosine in relation to vectors.
Tiven white
Messages
58
Reaction score
0

Homework Statement


The cosine of a vector is equal to the opposite over its magnitude.

Homework Equations



The attempt at a solution[/b] the cosine is the ratio of the adjacent to the hypothenuse this is why i say it "came' is incorrect.
 
Physics news on Phys.org
What exactly was the original question?
 
haruspex said:
What exactly was the original question?
That is the ?,its a true or false
 
Tiven white said:
That is the ?,its a true or false
What statement is true or false?

Oh, I see. It's this statement that's being questioned:
The cosine of a vector is equal to the opposite over its magnitude.

Yes, it's an incorrect statement, as you pointed out.
 
Last edited:
NascentOxygen said:
What statement is true or false?


If the cosine of a vector is its y component over its magnitude?
 
It's not the vector which has a cosine. It's only angles which have cosines.
 
Tiven white said:

Homework Statement


The cosine of a vector is equal to the opposite over its magnitude.
If this really is the statement, I would not say it was either "true" or "false". I would just say it is non-sense! The function "cosine" is not [g]defined[/b] for vectors, only for angles or numbers. Further, saying "the opposite" is non-sense. "Opposite" is an adjective not a noun and cannot take the article "the".

Homework Equations



The attempt at a solution
the cosine is the ratio of the adjacent to the hypothenuse this is why i say it "came' is incorrect.
 
Just out of curiosity, what is
Tiven white said:
this is why i say it "came' is incorrect.
supposed to mean?
 
vela said:
Just out of curiosity, what is
[ C A M ]
supposed to mean?

cosine = adjacent ÷ magnitude ?
 
  • #10
Wouldn't that be correct?
 
  • #11
vela said:
Wouldn't that be correct?
Clearly, OP is a little confused.
 
  • #12
cosine

NascentOxygen said:
Clearly, OP is a little confused.


The question was asking whether the statement ' cosine means the y component of a vector over its magnitude'.
Is this true or false?
 
  • #13
Tiven white said:
The question was asking whether the statement ' cosine means the y component of a vector over its magnitude'.
Is this true or false?
Definitely false.
 

Similar threads

Vectors Directions: Where is this Resultant Vector Pointing?
Replies
14
Views
1K
Is it possible to solve relative velocity problems without sine law?
Replies
25
Views
2K
Inclined Plane Vector Problem: Understanding the Use of Trigonometric Functions
Replies
3
Views
1K
Understanding Force Components in a Hanging Box System
Replies
12
Views
2K
How do I find Vector C in a non-right triangle using the Law of Cosines?
Replies
2
Views
1K
Dynamics: Relative Acceleration
Replies
2
Views
1K
Curious about Work done by Gravitational force
Replies
2
Views
1K
Finding Displacement: Sketch & Solve w/ Cosine Law
Replies
1
Views
1K
At what angle should the bomb be released?
Replies
4
Views
2K
Calculating the net force acting on an object from a diagram
Replies
9
Views
3K

Hot Threads

Recent Insights

Back
Top