$\sin (A+B)=\sin A \cos B+\cos A \sin B$ $\sin (A-B)=\sin A \cos B-\cos A \sin B$ $\cos (A+B)=\cos A \cos B-\sin A \sin B$ $\cos (A-B)=\cos A \cos B+\sin A \sin B$ $\tan (A+B)=\frac{\tan A+\tan B}{1-\tan A \tan B}$ $\tan (A-B)=\frac{\tan A-\tan B}{1+\tan A \tan B}$ ![[angle-sum-diagram.svg]] [[† Odd/Even Trigonometric Identities]]