Beginner's Verifying Trig Identity

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SUMMARY

The discussion focuses on verifying the trigonometric identity involving the expression $$(\cot \theta)(\sin \theta)$$. Participants clarify that $$\cot \theta$$ is defined as $$(\frac{\cos \theta}{\sin \theta})$$, leading to the simplification of the expression to $$\cos \theta$$. The confusion arises from the representation of $$\sin \theta$$ as a fraction, but it is established that the correct simplification does not require a denominator of 1. The final conclusion is that the expression simplifies to $$\cos \theta$$.

PREREQUISITES
  • Understanding of basic trigonometric identities, specifically cotangent and sine functions.
  • Familiarity with algebraic manipulation of fractions.
  • Knowledge of the unit circle and the definitions of trigonometric functions.
  • Ability to simplify expressions involving trigonometric functions.
NEXT STEPS
  • Study the derivation and properties of trigonometric identities.
  • Learn how to convert between different trigonometric functions, such as $$\tan \theta$$ and $$\cot \theta$$.
  • Practice simplifying complex trigonometric expressions using algebraic techniques.
  • Explore the unit circle to better understand the relationships between sine, cosine, and cotangent.
USEFUL FOR

Students learning trigonometry, mathematics educators, and anyone looking to strengthen their understanding of trigonometric identities and simplifications.

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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