Why Does This Logarithmic Trigonometric Equation Equal Zero?

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Homework Help Overview

The discussion revolves around a logarithmic trigonometric equation involving the tangent function and its properties. Participants are examining why the sum of logarithms of tangent values from 1° to 89° equals zero, and they are exploring the implications of this equation in the context of trigonometric identities and logarithmic properties.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants are attempting to prove the equation by manipulating logarithmic identities and exploring the sum of tangent values. Questions are raised about specific steps in the reasoning, particularly regarding the application of logarithmic properties and the validity of certain transformations. There is also a focus on identifying errors in the reasoning process.

Discussion Status

Some participants have provided guidance on how to approach the problem, suggesting a reevaluation of the logarithmic properties used. Others have pointed out potential errors in the original poster's reasoning, particularly concerning the application of logarithmic functions. The discussion is ongoing, with various interpretations and approaches being explored.

Contextual Notes

There are mentions of specific constraints related to the properties of logarithms and trigonometric functions, including undefined terms in certain cases. Participants are also discussing how to format equations in MathJax, indicating a focus on presentation as well as content.

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Homework Statement
Prove,
##\frac{1}{\log_{tan\ 1^\circ}(2021)} +\frac{1}{\log_{tan\ 2^\circ}(2021)} +\frac{1}{\log_{tan\ 3^\circ}(2021)} +...+\frac{1}{\log_{tan\ 89^\circ}(2021)} = 0 ##
Relevant Equations
-
The attempt at a solution

##

{\log_{2021}(tan\ 1^\circ)} +{\log_{2021}(tan\ 2^\circ)} +{\log_{2021}(tan\ 3^\circ)} +...+{\log_{2021}(tan\ 89^\circ)} = 0 \\

Antilog_{2021}[{\log_{2021}(tan\ 1^\circ)} +{\log_{2021}(tan\ 2^\circ)} +{\log_{2021}(tan\ 3^\circ)} +...+{\log_{2021}(tan\ 89^\circ)} ] = Antilog_{2021}[0]\\
tan\ 1^\circ + tan\ 2^\circ + tan\ 3^\circ +...+ tan\ 89^\circ = 1\\
arctan(tan\ 1^\circ + tan\ 2^\circ + tan\ 3^\circ +...+ tan\ 89^\circ = 1)\\
1^\circ +2^\circ +3^\circ +...+89^\circ = 45^\circ \\
\frac{89}{2} \times 90^\circ=45^\circ \\
##
Where did I make mistake?
I also want to know How to display a long equation in the same line in MathJax(Ex. 2nd line)
 
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Manasan3010 said:
Problem Statement: Proof,
The above should be Prove.
You prove (verb) a statement to arrive at a proof (noun).
Manasan3010 said:
##\frac{1}{\log_{tan\ 1^\circ}(2021)} +\frac{1}{\log_{tan\ 2^\circ}(2021)} +\frac{1}{\log_{tan\ 3^\circ}(2021)} +...+\frac{1}{\log_{tan\ 89^\circ}(2021)} = 0 ##
Relevant Equations: -

Working

##

{\log_{2021}(tan\ 1^\circ)} +{\log_{2021}(tan\ 2^\circ)} +{\log_{2021}(tan\ 3^\circ)} +...+{\log_{2021}(tan\ 89^\circ)} = 0 \\

Antilog_{2021}[{\log_{2021}(tan\ 1^\circ)} +{\log_{2021}(tan\ 2^\circ)} +{\log_{2021}(tan\ 3^\circ)} +...+{\log_{2021}(tan\ 89^\circ)} ] = Antilog_{2021}[0]##
The line below has an error.
##f(a + b + c) \ne f(a) + f(b) + f(c)##, in general.
Manasan3010 said:
##tan\ 1^\circ + tan\ 2^\circ + tan\ 3^\circ +...+ tan\ 89^\circ = 1\\
arctan(tan\ 1^\circ + tan\ 2^\circ + tan\ 3^\circ +...+ tan\ 89^\circ = 1)\\
1^\circ +2^\circ +3^\circ +...+89^\circ = 45^\circ \\
\frac{89}{2} \times 90^\circ=45^\circ \\
##
Where did I make mistake?
I also want to know How to display a long equation in the same line in MathJax(Ex. 2nd line)
 
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Mark44 said:
The line below has an error.
f(a+b+c)≠f(a)+f(b)+f(c)f(a+b+c)≠f(a)+f(b)+f(c)f(a + b + c) \ne f(a) + f(b) + f(c), in general.
Which line are you referring to and What should I to get the correct steps?
 
Manasan3010 said:
Which line are you referring to and What should I to get the correct steps?
The second and third lines of your work.
Manasan3010 said:
##Antilog_{2021}[{\log_{2021}(tan\ 1^\circ)} +{\log_{2021}(tan\ 2^\circ)} +{\log_{2021}(tan\ 3^\circ)} +...+{\log_{2021}(tan\ 89^\circ)} ] = Antilog_{2021}[0]##
The line below doesn't follow from the line above.
Manasan3010 said:
##tan\ 1^\circ + tan\ 2^\circ + tan\ 3^\circ +...+ tan\ 89^\circ = 1##
You are in essence saying that ##f(a + b + c) = f(a) + f(b) + f(c)##, which is generally not true.

Start in again with your first line:
##\log_{2021}(\tan 1^\circ) +\log_{2021}(\tan 2^\circ) +\log_{2021}(\tan 3^\circ) +...+\log_{2021}(\tan 89^\circ) = 0##

Use the idea that ##\log_b(A) + \log_b(B) = \log_b(AB)##
 
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I found the solution Thanks.

If anyone looking for solution Then,
tan1 .tan2 .tan3……tan87 .tan88. tan89

tan1 . tan 2 . tan 3 ….. cot3. cot 2. cot 1

tan1.cot1 . tan2.cot2 …..tan44.cot44. tan45

1*1*1*1…….1
 
There's actually an issue with the problem as stated. The middle term of the series would be
$$\frac 1{\log_{\tan 45^\circ}2021},$$ but the logarithm is undefined since there's no power of 1 that's equal to 2021.
 
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