Verify That Each Equation Is an Identity $$\cot ( 2 \theta ) = \frac { \csc ^ { 2 } \theta - 2 } { 2 \cot \theta }$$

Verify that each equation is an identity.
- $$\cot ( 2 \theta ) = \frac { \csc ^ { 2 } \theta - 2 } { 2 \cot \theta }$$