Skip to main content
Ch. 6 - Inverse Circular Functions and Trigonometric Equations
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161, 9780135440780, 9780136881117, 9780135440827, 9780135924891Non è quello che usi tu?Cambia libro di testo
Capitolo 7, Problema 4

Use the unit circle shown here to solve each simple trigonometric equation. If the variable is x, then solve over [0, 2π). If the variable is θ, then solve over [0°, 360°).                     
<IMAGE>
sin x = ―√3/2

Guida verificata passo dopo passo
1
Identify the trigonometric function and the given value: here, we have \( \sin x = -\frac{\sqrt{3}}{2} \).
Recall the unit circle values where \( \sin \theta = \pm \frac{\sqrt{3}}{2} \). The positive value \( \frac{\sqrt{3}}{2} \) corresponds to angles \( \frac{\pi}{3} \) and \( \frac{2\pi}{3} \), so the negative value will correspond to angles in the third and fourth quadrants.
Determine the reference angle: since \( \sin x = -\frac{\sqrt{3}}{2} \), the reference angle is \( \frac{\pi}{3} \).
Find the angles in the interval \( [0, 2\pi) \) where sine is negative with the reference angle \( \frac{\pi}{3} \). These are \( \pi + \frac{\pi}{3} \) and \( 2\pi - \frac{\pi}{3} \).
Write the solutions explicitly as \( x = \frac{4\pi}{3} \) and \( x = \frac{5\pi}{3} \), which are the values of \( x \) in the interval \( [0, 2\pi) \) satisfying the equation.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.

Concetti chiave

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

Unit Circle and Angle Measurement

The unit circle is a circle with radius 1 centered at the origin of the coordinate plane. Angles on the unit circle are measured in radians (0 to 2π) or degrees (0° to 360°), and each angle corresponds to a point on the circle whose coordinates represent cosine and sine values. Understanding this helps identify angles where sine or cosine take specific values.
Video consigliato:
Percorso guidato
06:11
Introduction to the Unit Circle

Sine Function and Its Values on the Unit Circle

The sine of an angle corresponds to the y-coordinate of the point on the unit circle at that angle. Knowing the common sine values, such as ±√3/2, and their corresponding angles allows solving equations like sin x = -√3/2 by finding all angles in the given interval with that sine value.
Video consigliato:
Percorso guidato
6:34
Sine, Cosine, & Tangent on the Unit Circle

Solving Trigonometric Equations Over a Specified Interval

When solving trigonometric equations, it is essential to find all solutions within the given domain, such as [0, 2π) for radians or [0°, 360°) for degrees. This involves identifying all angles where the trigonometric function equals the given value, considering the function’s periodicity and symmetry on the unit circle.
Video consigliato:
Percorso guidato
4:34
How to Solve Linear Trigonometric Equations