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general solution of tan x+tan4x+tan7x=tanxtan4xtan8x

param , 11 Years ago

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1 Answers

Jitender Singh

Ans:Hello student, please find answer to your question
$tanx + tan4x + tan7x = tanx.tan4x.tan8x$
$tan7x = tan(8x-x) = \frac{tan8x - tanx}{1+tanx.tan8x}$
$tanx + tan4x + tan7x = tanx.tan4x.tan8x$
$tanx + tan4x +\frac{tan8x - tanx}{1+tanx.tan8x}= tanx.tan4x.tan8x$
$tanx + tan4x + tan^{2}x.tan8x + tanx.tan4x.tan8x+tan8x - tanx= tanx.tan4x.tan8x+tan^{2}x.tan4x.tan^{2}8x$ $tan4x + tan^{2}x.tan8x + tan8x = tan^{2}x.tan4x.tan^{2}8x$
$tan4x + tan8x = tan^{2}x.tan8x(tan4x.tan8x-1)$
$tan4x + tan8x = -tan^{2}x.tan8x(1-tan4x.tan8x)$
$\frac{tan4x + tan8x}{1-tan4x.tan8x}= -tan^{2}x.tan8x$
$tan12x= -tan^{2}x.tan8x$
Hope you can solve it from here.

Last Activity: 11 Years ago