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Ch. 2 - Acute Angles and Right Triangles
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161Not the one you use?Change textbook
Chapter 3, Problem 64

Give the exact value of each expression. See Example 5. csc 60°

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Recall that the cosecant function is the reciprocal of the sine function, so \(\csc \theta = \frac{1}{\sin \theta}\).
Identify the angle given: \(60^\circ\).
Find the exact value of \(\sin 60^\circ\). From the special angles in trigonometry, \(\sin 60^\circ = \frac{\sqrt{3}}{2}\).
Use the reciprocal relationship to write \(\csc 60^\circ = \frac{1}{\sin 60^\circ} = \frac{1}{\frac{\sqrt{3}}{2}}\).
Simplify the expression by multiplying numerator and denominator appropriately to find the exact value of \(\csc 60^\circ\).

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Key Concepts

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

Definition of Cosecant (csc)

Cosecant is the reciprocal of the sine function. For any angle θ, csc(θ) = 1/sin(θ). Understanding this relationship allows you to find the cosecant value by first determining the sine of the angle.
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Exact Values of Sine for Special Angles

Certain angles like 30°, 45°, and 60° have well-known exact sine values derived from special right triangles. For 60°, sin(60°) = √3/2, which is essential for calculating csc(60°) exactly.
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Reciprocal Function Calculation

To find the exact value of csc(60°), you take the reciprocal of sin(60°). This involves flipping the fraction representing sin(60°), turning √3/2 into 2/√3, which can be simplified further if needed.
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