Prove $\cos \left( x - \frac { \pi } { 2 } \right) + \cos \left( x + \frac { \pi } { 2 } \right) = 0$

question 29

Essay

Prove $\cos \left( x - \frac { \pi } { 2 } \right) + \cos \left( x + \frac { \pi } { 2 } \right) = 0$ .

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Definitions:

Debit

A bookkeeping record that raises the value of an asset or expense, or reduces the value of a liability or equity.

Expense Account

An account used to record expenditures incurred by a company, relating to its operational activities.

Supplies

Items used in the day-to-day operations of a business, typically consumable in nature, such as office supplies, cleaning materials, and manufacturing components.

Accounts Payable

Accounts payable are liabilities of a business that represent its obligations to pay off a short-term debt to its creditors or suppliers.