Prove the Identity $$\cos \left( x + \frac { \pi } { 2 } \right) + \sin \left( x + \frac { \pi } { 2 } \right) = \cos x - \sin x$$

question 107

Essay

Prove the identity. $$\cos \left( x + \frac { \pi } { 2 } \right) + \sin \left( x + \frac { \pi } { 2 } \right) = \cos x - \sin x$$

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Definitions:

Behavioral Economists

Researchers in economics focusing on how psychological, cognitive, emotional, cultural, and social aspects influence the economic choices made by individuals and institutions.

Availability Heuristic

A mental heuristic that uses the most readily accessible examples in someone's memory to appraise a specific area, concept, technique, or decision-making process.

Behavioral Economists

Scholars who study the effects of psychological, cognitive, emotional, cultural, and social factors on the economic decisions of individuals and institutions.

Payroll Deduction

A method where an employer withholds a portion of an employee's salary for taxes, insurance premiums, or contributions to retirement plans, directly reducing the employee's take-home pay.