#### Cotangent of the sum of two angles

cosota

Trigonometry

The cotangent of the sum of two angles equals the product of the cotangents of the angles minus 1 divided by the sum of the cotangents of the two angles

\cot(\alpha+\beta) = \dfrac{\cot \alpha\cot \beta-1 }{\cot \alpha+\cot \beta}

or