Why Does tan x Have This Domain?

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SUMMARY

The domain of the tangent function, tan(x), is defined as the set of values where the function is undefined, specifically at {(2n+1)π/2, n∈I}, due to the cosine function equating to zero at these points. The tangent function is expressed as tan(x) = sin(x)/cos(x), indicating that it is undefined whenever cos(x) = 0. The discussion clarifies that this set represents the complement of the domain, meaning it lists the x-values where tan(x) does not exist, while the range of tan(x) encompasses all real numbers.

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shihab-kol
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I found in a book that the domain of tan x was {(2n+1)π/2 , n∈I}
The graph however shows that for every value of x , the function takes on a value .So, why is the domain like this?
 
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shihab-kol said:
I found in a book that the domain of tan x was {(2n+1)π/2 , n∈I}
The graph however shows that for every value of x , the function takes on a value .So, why is the domain like this?
##\tan(x) = \frac{\sin(x)}{\cos(x)}## so whenever ##\cos(x) =0## then ##\tan(x)## isn't defined.
 
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shihab-kol said:
I found in a book that the domain of tan x was {(2n+1)π/2 , n∈I}
That set is the complement of the domain of the tan function -- the set of x values where tan x is undefined.
 
So that set does not reflect the defined values of the function,just the undefined ones. Right?
Correct me if I am wrong.
 
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shihab-kol said:
So that set does not reflect the defined values of the function,just the undefined ones. Right?
Correct me if I am wrong.
The set you wrote in post #1 is not the defined values of the function. The range of the tangent function (set of all output values) is all real numbers. That set in post #1 lists (by a formula) all of the numbers that are not in the domain of tan(x).
 
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