设:arcsec(1325/357)为αarcsec(1325/357)=α∴secα=1325/357∴cosα=1/secα=1/﹙1325/357﹚=357/1325 sinα=√﹙1-cos²α﹚=√[1-﹙357/1325﹚²]=√﹙[﹙1+357/1325﹚×﹙1-357/1325﹚]=√﹙1682/1325×968/1325]=√﹙1682×968﹚/1325²]=√﹙841×2×2×484﹚/1325²]=√﹙29²×2²×22²/1325²﹚=﹙29×2×22﹚/1325=1276/1325 cotα=cosα/sinα=﹙357/1325﹚/﹙1276/1325﹚=357/1276∴cot[arcsec(1325/357)]=357/1276