Question

2-sin^2x/cos2x=sec^2x+1

Answer 1

\[ 2 -\frac {\sin^2(x)}{\cos^2(x)}= \sec^2(x) +1\\
2 -\tan^2(x) = 1+ \tan^2(x) +1\\
2\tan^2(x)=0\\
\tan(x)=0\\
x= k \pi,\,\, k=0,\pm 1 ,\pm 2 ,\pm 3, \cdots

\]