Skip to main content
Ch. 3 - Trigonometric Identities and Equations
Blitzer - Trigonometry 3rd Edition
Blitzer3rd EditionTrigonometryISBN: 9780137316601Non è quello che usi tu?Cambia libro di testo
Capitolo 3, Problema 3.3.51

In Exercises 47–54, use the figures to find the exact value of each trigonometric function. cos(α/2)

Guida verificata passo dopo passo
1
Identify the given angle \( \alpha \) and the trigonometric function you need to find, which in this case is \( \cos \alpha \).
Recall the definition of cosine in a right triangle: \( \cos \alpha = \frac{\text{adjacent side}}{\text{hypotenuse}} \).
Examine the figure provided (usually a right triangle) to determine the lengths of the adjacent side and the hypotenuse relative to angle \( \alpha \).
Substitute the lengths of the adjacent side and hypotenuse into the cosine ratio formula: \( \cos \alpha = \frac{\text{adjacent}}{\text{hypotenuse}} \).
Simplify the fraction if possible to find the exact value of \( \cos \alpha \).

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
4m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Trigonometric Functions

Trigonometric functions like sine, cosine, and tangent relate the angles of a right triangle to the ratios of its sides. Understanding these functions is essential for finding exact values based on given angles or side lengths.
Video consigliato:
Percorso guidato
6:04
Introduction to Trigonometric Functions

Unit Circle and Angle Measures

The unit circle represents angles and their corresponding trigonometric values on a circle of radius one. Knowing how to interpret angles in radians or degrees on the unit circle helps in determining exact trigonometric values.
Video consigliato:
Percorso guidato
06:11
Introduction to the Unit Circle

Reference Angles and Quadrants

Reference angles are acute angles used to find trigonometric values for angles in different quadrants. Recognizing the quadrant of the angle helps determine the sign (positive or negative) of the trigonometric function.
Video consigliato:
Percorso guidato
5:31
Reference Angles on the Unit Circle