Prove the Identity $$\cot ^ { 2 } x = ( \csc x - 1 ) ( \csc x + 1 )$$

question 129

Essay

Prove the identity.
- $$\cot ^ { 2 } x = ( \csc x - 1 ) ( \csc x + 1 )$$

---

Definitions:

Lymph Node Dissection

A surgical procedure to remove one or more lymph nodes, often used in the treatment of cancer to prevent its spread.

BD Eclipse

A brand and model of safety needle designed to prevent needlestick injuries among healthcare professionals.

Blood Collection Needle

A medical device specifically designed for drawing blood from a vein for diagnostic or treatment purposes.

Arterial Puncture

A medical procedure involving the puncturing of an artery with a needle to obtain a blood sample or measure arterial blood gases.