Prove $\sin ( x + y ) + \sin ( x - y ) = 2 \sin x \cos y$

question 37

Essay

Prove $\sin ( x + y ) + \sin ( x - y ) = 2 \sin x \cos y$ .

---

Definitions:

Authoritarian

A style of governance or leadership characterized by strict obedience, control, and authority, often with little regard for individual freedom and autonomy.

Sibling Intimacy

A close and affectionate relationship between siblings, marked by shared experiences, emotional support, and mutual understanding.

Emotional Understanding

The awareness and comprehension of one’s own and others’ emotions, including recognizing and identifying feelings.

Adjustment Problems

Difficulties in coping or adapting to new, changing, or challenging environments, often leading to psychological distress or disorders.