Verifying Trigonometric Identities

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SUMMARY

The discussion centers on verifying the trigonometric identity \(\frac{\cot x - \tan x}{\sin x \cos x} = \csc^2 x - \sec^2 x\). The original poster struggled with algebraic manipulation and correctly identifying the identity due to a typographical error. A key suggestion was to split the left-hand side into two separate fractions to simplify the verification process. This approach is essential for successfully proving the identity.

PREREQUISITES
  • Understanding of fundamental trigonometric identities
  • Proficiency in algebraic manipulation of fractions
  • Familiarity with the definitions of cotangent, tangent, cosecant, and secant
  • Knowledge of how to convert between sine and cosine functions
NEXT STEPS
  • Practice verifying trigonometric identities using different algebraic techniques
  • Learn how to manipulate complex fractions in trigonometric expressions
  • Study the derivation and application of fundamental trigonometric identities
  • Explore common mistakes in trigonometric identity verification and how to avoid them
USEFUL FOR

Students studying trigonometry, mathematics educators, and anyone looking to improve their skills in verifying trigonometric identities.

misssue
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I have been having lots of trouble verifying trigonometric identities. I know the fundamental identities but I am actually having trouble with the algebra that goes along with the problems.
The problem I am working on now is:

cos(x)-tan(x)/sin(x)cos(x) = csc^2 (x) - sec^2 (x)

(The csc and sec are squared. I didn't know the best way to right that on here)

I tried to change everything to sin/cos but I felt like I made the equation much more confusing doing that.

I got:

(cos(x)/sin(x))-(sin(x)/cos(x))/(sin(x)cos(x)) = (1/sin(x))^2 - (1/cos(x))^2

I am more than a little lost.

I also tried it by changing only the left side and got:

(cot(x)-tan(x)) (1/sin(x)) (1/cos(x))

With either option I don't know where to go next and I'm not even sure if I started correctly.
 
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misssue said:
I have been having lots of trouble verifying trigonometric identities. I know the fundamental identities but I am actually having trouble with the algebra that goes along with the problems.
The problem I am working on now is:

cos(x)-tan(x)/sin(x)cos(x) = csc^2 (x) - sec^2 (x)

(The csc and sec are squared. I didn't know the best way to right that on here)
Looks like you have a typo there, because as written the LHS won't simplify to the RHS. I think you mean this:
\frac{\cot x - \tan x}{\sin x \cos x} = \csc^2 x - \sec^2 x

(Also, "right" should be "write".)

In which case, why don't you start by splitting the LHS into a difference of 2 fractions and go from there.
 
I feel silly for writing "write" as "right". There was a typo. Thank you for figuring that out and for the tip!
 

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