Did I Make a Mistake in my Coordinates? Help Needed!

In summary, the conversation discusses the coordinates of point B in a diagram and whether they should be (-a cos theta, a sin theta) instead of (a cos theta, a sin theta). It is clarified that the labeling of the coordinates is correct and that the x-coordinate should be negative due to the position of the origin. The conversation ends with the issue being resolved and the person thanking the other for their help.
  • #1
Shafia Zahin
31
1
In the attached pic,it is shown that the coordinates of point B are (a cos theta, a sin theta) ,but shouldn't it be (-a cos theta,a sin theta)? Can anybody please help?
 

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  • #2
No there is nothing wrong with the labeling of the coordinates in the diagram. Recall that ##\cos \theta## is negative for ##\pi/2 < \theta < 3\pi/2## (or what you may know as the second and third quadrants).
 
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  • #3
Fightfish said:
No there is nothing wrong with the labeling of the coordinates in the diagram. Recall that ##\cos \theta## is negative for ##\pi/2 < \theta < 3\pi/2## (or what you may know as the second and third quadrants).
But didn't it come like this?(see the attachment)
 

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  • #4
When you did the triangle construction in your diagram, you treated ##x## there as a length, which only takes on positive values, but ignored its position relative to where the origin was defined. So, the x-coordinate of the point should in fact be the negative of the ##x## in your derivation.
 
  • #5
Fightfish said:
When you did the triangle construction in your diagram, you treated ##x## there as a length, which only takes on positive values, but ignored its position relative to where the origin was defined. So, the x-coordinate of the point should in fact be the negative of the ##x## in your derivation.
Oh,now I got it,thank you so much:smile:
 

1. What is "confusion in coordinates"?

"Confusion in coordinates" refers to a situation where there is a discrepancy or inconsistency in the way that coordinates are defined or used. This can lead to confusion and errors in data analysis or navigation.

2. How does confusion in coordinates occur?

Confusion in coordinates can occur due to a variety of factors, such as using different coordinate systems, incorrect conversions between units, human error in recording or interpreting coordinates, or outdated or inaccurate data.

3. What are the consequences of confusion in coordinates?

The consequences of confusion in coordinates can range from minor errors in data analysis to significant problems in navigation or mapping. It can also lead to delays or mistakes in scientific research or engineering projects.

4. How can confusion in coordinates be avoided?

To avoid confusion in coordinates, it is important to clearly define and use a consistent coordinate system, properly convert between units, double-check data for accuracy, and regularly update and verify data sources.

5. What are some examples of confusion in coordinates in scientific research?

One example of confusion in coordinates in scientific research is when different data sets use different coordinate systems, leading to difficulty in comparing or combining them. Another example is when a study uses outdated or incorrect coordinate data, leading to inaccurate conclusions or models.

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