cos−1y1+y2\cos ^{-1} \frac{y}{\sqrt{1+y^{2}}}cos−11+y2y
cos−111+y2\cos ^{-1} \frac{1}{\sqrt{1+y^{2}}}cos−11+y21
tan−1y\tan ^{-1} ytan−1y
sin−1y1+y2\sin ^{-1} \frac{y}{\sqrt{1+y^{2}}}sin−11+y2y