2.8.4 负角公式

$$\begin{array}{}\text{(2.151)}& \arcsin \left(-x\right)=-\arcsin x,\end{array}$$$$\begin{array}{}\text{(2.152)}& \arctan \left(-x\right)=-\arctan x,\end{array}$$$$\begin{array}{}\text{(2.153)}& \arccos \left(-x\right)=\pi -\arccos x,\end{array}$$$$\begin{array}{}\text{(2.154)}& \mathrm{arccot}\left(-x\right)=\pi -\mathrm{arccot}x.\end{array}$$