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Ask iit jee aieee pet cbse icse state board community Community Discussion Question: Solve this equation.
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pantpranav (352)

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Solve:
tan + tan ( + /3) + tan ( + 2/3) = 3.



    
goldknight (395)

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your question has not come up correctly !!
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Greatdreams (3155)

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I guess this is the problem :

Well tan pi/3 = 3

tan  (2pi/3)  =  tan (pi - pi/3) = - 3

So you have tan x + tan (x + pi/3) +tan (x + 2pi/3)

=tan x + [tan x + 3]/(1 - 3 tan x ) + ( tan x - 3)/(1+ 3 tan x)

=tan x(1 - 3 tan 2 x ) + (tan x + 3)(1 + 3 tan x) + (tan x - 3)(1 - 3 tan x)
                                  1 - 3 tan 2 x

= 9 tan x - 3 tan 3 x/ 1 - 3 tan 2 x  = 3 (3tan x - tan 3 x)/1 - 3tan 2 x

= 3 tan 3x

So 3 tan 3 x = 3

Hence 3x = n pi + pi/4

So x = n pi/3 + pi/12

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