12tan−12425\frac{1}{2} \tan ^{-1} \frac{24}{25}21tan−12524
12sin−12425\frac{1}{2} \sin ^{-1} \frac{24}{25}21sin−12524
12sin−1247\frac{1}{2} \sin ^{-1} \frac{24}{7}21sin−1724
12tan−1724\frac{1}{2} \tan ^{-1} \frac{7}{24}21tan−1247