Coordinate angles of three dimensional vectors

AI Thread Summary
If two coordinate angles of a three-dimensional vector are known, the possibility for determining the third coordinate angle is not unlimited; the statement is false. The sum of the squares of the three direction cosines equals one, which restricts the values of the third angle. The discussion emphasizes that while there are methods to calculate the third angle, the number of valid solutions is finite. The confusion arises from the interpretation of "unlimited" in the context of possible angles. Ultimately, the conclusion is that knowing two angles does not lead to an infinite number of possibilities for the third angle.
Tiven white
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Homework Statement


If u know the value of two coordinate angles there is an ulimeted amount of possibility for finding the third coordinate angle
A. True
B. False

Homework Equations





The Attempt at a Solution


I .not too sure about this one any suggestions would be appreciated I think its tfalse hough
 
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Tiven white said:

Homework Statement


If u know the value of two coordinate angles there is an ulimeted amount of possibility for finding the third coordinate angle
A. True
B. False

Homework Equations





The Attempt at a Solution


I .not too sure about this one any suggestions would be appreciated I think its tfalse hough
What is the sum of the squares of the three direction cosines equal to?
 
Chestermiller said:
What is the sum of the squares of the three direction cosines equal to?
they sum to 1
 
Two coordinate angles? Angles between vectors? I don't understand the question.
 
Tiven white said:
they sum to 1

Does that help answer your question?
 
Tiven white said:
they sum to 1

This approach works, but it might also help to think of it geometrically. What shape is formed by the set of lines at a given angle to the positive half of an axis?
 
Chestermiller said:
Does that help answer your question?


I'm only confuse of the term unlimited I know there is the method of just subtracting the squared Cosine of the other angles from one to get the third though I'm unsure about the term unlimited since even though I know that's a method I Dont know if its the only method
 
Tiven white said:
I'm only confuse of the term unlimited I know there is the method of just subtracting the squared Cosine of the other angles from one to get the third though I'm unsure about the term unlimited since even though I know that's a method I Dont know if its the only method
The question isn't asking about different methods of finding the answer; it's asking if the number of solution values is unlimited. You can use whatever method you like.
 
haruspex said:
The question isn't asking about different methods of finding the answer; it's asking if the number of solution values is unlimited. You can use whatever method you like.


Its false right?
 
  • #10
Tiven white said:
Its false right?

Yes. How many possibilities are there for the third angle?
 

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