www . seprodstore . com 13 � Reciprocal trigonometric ratios : 1 . 1 cosec sin � � � 2 . 1 sec cos � � � 3 . 1 cot tan � � � � Inverse trigonometric functions : 1 . 1 1 ( ) sin ( ) sin arcsin f x x f x x x � � � � � � 2 . 1 1 ( ) cos ( ) cos arccos g x x g x x x � � � � � � 3 . 1 1 ( ) tan ( ) tan arctan h x x h x x x � � � � � � � More trigonometric identities : 1 . 2 2 sec 1 tan � � � � 2 . 2 2 cosec 1 cot � � � � � 2 2 tan tan 2 1 tan � � � � � : Double angle formula for tangent ratio