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Ch. 1 - Angles and the Trigonometric Functions
Blitzer - Trigonometry 3rd Edition
Blitzer3rd EditionTrigonometryISBN: 9780137316601Not the one you use?Change textbook
Chapter 1, Problem 29

In Exercises 29–34, convert each angle in degrees to radians. Round to two decimal places. 18°

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1
Recall the formula to convert degrees to radians: \(\text{radians} = \text{degrees} \times \frac{\pi}{180}\).
Substitute the given angle in degrees into the formula: \(18^\circ \times \frac{\pi}{180}\).
Simplify the fraction \(\frac{18}{180}\) to its lowest terms.
Multiply the simplified fraction by \(\pi\) to express the angle in radians.
If needed, use the approximate value of \(\pi \approx 3.1416\) to calculate a decimal value and round it to two decimal places.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Degree to Radian Conversion

Degrees and radians are two units for measuring angles. To convert degrees to radians, multiply the degree measure by π/180. This conversion is essential because radians are the standard unit in many trigonometric calculations.
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Understanding Radians

A radian measures an angle based on the radius of a circle; one radian is the angle subtended by an arc equal in length to the radius. There are 2π radians in a full circle, making radians a natural unit for trigonometry and calculus.
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Rounding and Approximation

After converting degrees to radians, results often need to be rounded for simplicity. Rounding to two decimal places means keeping two digits after the decimal point, which balances precision and readability in practical problems.
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