This is LaTeX code:
[latex]
f(x)= \ln \frac{1 + \sqrt{\sin x}}{1 - \sqrt{\sin x}} + 2 \cdot \arctan \sqrt{\sin x}= \ln \frac{1 + \sqrt{\sin x}}{1 - \sqrt{\sin x}}' + 2 \cdot \arctan \sqrt{\sin x}'=
[/latex]