Question

Help me please: tan3x-tanx-1=0​

Answer 1

Answer: $x=0.30714\dots +\pi n$

Step-by-step explanation:

$\Rightarrow \tan3x-\tan x-1=0\\\\\Rightarrow \dfrac{3\tan x-\tan ^3x}{1-3\tan ^2x}-\tan x-1=0\\\\\Rightarrow 3\tan x-\tan ^3x+( 1-3\tan ^2x)(-1-\tan x)=0\\\Rightarrow 3\tan x-\tan ^3x-1-\tan x+3\tan ^2x+3\tan ^3 x=0\\\Rightarrow 2\tan ^3x+3\tan ^2x+2\tan x-1=0\\\Rightarrow \tan \left(x\right)\approx \:0.31718$