PHP 忒聊 綴豖 ヶ輛 atan (PHP 3, PHP 4) 鏡扴 殿隙 arg 腔毀淏з硉ㄛ等弇岆說僅﹝ atan() 岆 tan() 腔毀滲杅ㄛ坳腔砩佷岆婓 atan() 毓峓爵腔藩跺硉飲岆 a==tan(atan(a)) ﹝ See also atanh(), asin() and acos(). 綴豖 れ萸 ヶ輛 atan2 奻珨撰 atanh