Use an Identity to Write the Expression as a Single $2 \cos ^ { 2 } 22.5 ^ { \circ } - 1$

question 259

Multiple Choice

Use an identity to write the expression as a single trigonometric function or as a single number.
- $2 \cos ^ { 2 } 22.5 ^ { \circ } - 1$

• A) \(\frac { \sqrt { 2 } } { 4 }\)
• B) \(\frac { \sqrt { 3 } } { 3 }\)
• C) \(\sqrt { 3 }\)
• D) \(\frac { \sqrt { 2 } } { 2 }\)

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Definitions:

Average Tax Rate

The ratio of the total amount of taxes paid to the total income, showing the percentage of income paid in taxes.

Progressive Tax

A taxation system where the tax rate increases as the taxable amount (income or profits) increases, making it proportionately more taxing on higher earners.

Income Increases

Refers to a situation where an individual's or entity's earnings grow over a period, leading to higher financial resources.

Taxable Income

The portion of an individual's or organization's income that is subject to federal, state, or other forms of taxation.