1
Simplifier \(\arctan \frac {1-x}{1+x}\).
2
Simplifier \(\arctan \sqrt{\frac {1-x}{1+x}}\).
3
Simplifier \(\arctan\frac{x-\sqrt{1-x^2}}{x+\sqrt{1-x^2}}\).
4
Simplifier \(\arctan\frac{\sqrt{x^2+1}-1}x + \arctan\bigl(\sqrt{1+x^2} - x\bigr)\).
5
Simplifier \(\arctan \frac1{2x^2} - \arctan\frac x{x-1} + \arctan\frac{x+1}x\).