Help with solving trig identity problem It's been 20 years since I did trig, and this one seems a little tricky. How would I solve 
$$
\tan^2(x) -2\tan(x)=1
$$
with steps?

$$\tan ^{ 2 }{ x-2\tan { x } -1=0 } \\ \tan ^{ 2 }{ x-2\tan { x } +1-2=0 } \\ { \left( \tan { x } -1 \right)  }^{ 2 }-2=0\\ \tan { x-1=\pm \sqrt { 2 }  } \\ \tan { x } =1\pm \sqrt { 2 } \\ x=\arctan { \left( 1\pm \sqrt { 2 }  \right) +\pi n } \\ $$
