Beginner's Verifying Trig Identity

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Discussion Overview

The discussion revolves around verifying a trigonometric identity involving cotangent and sine. Participants explore the transformation of the expression $$(\cot \theta)(\sin \theta)$$ and the appropriate representation of sine as a fraction. The context is primarily conceptual and involves mathematical reasoning.

Discussion Character

  • Exploratory, Technical explanation, Mathematical reasoning

Main Points Raised

  • One participant expresses confusion about converting $$(\sin \theta)$$ into a fraction, questioning whether it should be $$(\frac{1}{\sin \theta})$$ or $$(\frac{\sin \theta}{1})$$.
  • Another participant correctly identifies that $$(\cot \theta)$$ is defined as $$(\frac{\cos \theta}{\sin \theta})$$, correcting a previous error.
  • There is a discussion about whether the representation of sine as a fraction is necessary, with one participant suggesting that $$(\frac{\sin \theta}{1})$$ is valid but unnecessary.
  • One participant concludes that the result of the expression simplifies to $$(\cos \theta)$$ after the transformations.
  • A later post reiterates the definition of tangent as $$(\tan \theta = \frac{\sin \theta}{\cos \theta})$$, but its relevance to the main discussion is unclear.

Areas of Agreement / Disagreement

Participants generally agree on the definition of cotangent, but there is some confusion regarding the representation of sine and whether the denominator is necessary. The discussion does not reach a consensus on the necessity of certain steps in the simplification process.

Contextual Notes

There are unresolved questions about the representation of sine and the implications of including or excluding the denominator in the fraction. The discussion also reflects varying levels of understanding among participants.

Who May Find This Useful

This discussion may be useful for beginners in trigonometry who are trying to understand the manipulation of trigonometric identities and the representation of functions as fractions.

courtbits
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$$(\cot \theta)(\sin \theta)$$

So far I understand that you can make
$$(\cot a) \implies (\frac{\cos \theta}{\sin \theta})$$

Then it would come to
$$(\frac{\cos \theta}{\sin \theta})(\sin \theta)$$

I'm stuck at when making $$(\sin \theta)$$ into a fraction.

The sine in between the asterisks is what I mean:
$$(\frac{\cos \theta}{\sin \theta}) *(\sin \theta)*$$

I have no idea if the fraction needs to be:
$$(\frac{1}{\sin \theta})$$

OR

$$(\frac{\sin \theta}{1})$$

I know it's silly to ask over, but also how to proceed the problem.

The answer choices are ~

a.) $$\tan \theta$$
b.) $$\cos \theta$$

I would really like to know which answer it is, and the reason behind it.
*Thanks in advance!
 
Last edited:
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courtbits said:
$$(\cot \theta)(\sin \theta)$$

$$(\cot a) \implies (\frac{\sin \theta}{\cos \theta})$$
!

No

$$\cot \theta = (\frac{\cos \theta}{\sin \theta})$$
 
kaliprasad said:
No

$$\cot \theta = (\frac{\cos \theta}{\sin \theta})$$

Wow. x.x A typo error. I will fix it. XD
 
courtbits said:
$$(\cot \theta)(\sin \theta)$$

So far I understand that you can make
$$(\cot a) \implies (\frac{\cos \theta}{\sin \theta})$$

Then it would come to
$$(\frac{\cos \theta}{\sin \theta})(\sin \theta)$$

I'm stuck at when making $$(\sin \theta)$$ into a fraction.

The sine in between the asterisks is what I mean:
$$(\frac{\cos \theta}{\sin \theta}) *(\sin \theta)*$$
!
\
now you are right till this point then the mistake
 
kaliprasad said:
\
now you are right till this point then the mistake

Would it be $$(\frac{\cos \theta}{\sin \theta})(\frac{\sin \theta}{1})$$?
 
courtbits said:
Would it be $$(\frac{\cos \theta}{\sin \theta})(\frac{\sin \theta}{1})$$?
yes but 1 in denominator is unnecessary and result becomes

$$\cos \theta$$
 
kaliprasad said:
yes but 1 in denominator is unnecessary and result becomes

$$\cos \theta$$

Oh OH! I got it! Now I understand! XD Thank you very much!
 
tan θ = sin θ/cos θ
 

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