The teachers’ library›TrigonometryCompound angle formulassin(A±B)=sinAcosB±cosAsinBsin(A±B)=sinAcosB±cosAsinBcos(A±B)=cosAcosB∓sinAsinBcos(A±B)=cosAcosB∓sinAsinBtan(A±B)=1∓tanAtanBtanA±tanBtan(A±B)=tanA±tanB1∓tanAtanBOpen on a new board The board is kept in this browser only, like your other boards. On any board, the Library button adds this too.More in TrigonometrySOH CAH TOAPythagorean identitiesReciprocal trigonometric functionsExact valuesDouble angle formulasHalf-angle and power-reducing formulasSum-to-product formulasCofunction and symmetry identitiesGeneral solutions of trigonometric equationsRadians and degrees