Use Sum and Difference Formulas for Cosines and Sines
- $\cos 285 ^ { \circ }$

question 9

Multiple Choice

Use Sum and Difference Formulas for Cosines and Sines
- $\cos 285 ^ { \circ }$

• A) \(\frac { \sqrt { 2 } ( \sqrt { 3 } - 1 ) } { 4 }\)
• B) \(- \frac { \sqrt { 2 } ( \sqrt { 3 } - 1 ) } { 4 }\)
• C) \(- \sqrt { 2 } ( \sqrt { 3 } + 1 )\)
• D) \(- \sqrt { 2 } ( \sqrt { 3 } - 1 )\) Find the exact value of the expression.

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Definitions:

Tax

A compulsory financial charge or other levy imposed by a government on individuals or businesses to fund various public expenditures.

Binding Price Floor

A legal minimum price for a good or service that is set above the equilibrium price, resulting in surpluses.

Binding Price Ceiling

A government-imposed limit on how high a price can be charged for a product, set below the market equilibrium price, leading to shortages.

Decreases

A reduction in size, quantity, or degree; the opposite of increases.