### Mathematics Exercise: Trigonometric Functions #### Question: Evaluate the following using exact degree measure. Show all of your work. \[ \sec^{-1} \left( \frac{2\sqrt{3}}{3} \right) \] #### Multiple Choice Answers: - [ ] 60° - [ ] 150° - [ ] 30° - [ ] 120° #### Explanation: To solve the given problem, recall that the secant function is the reciprocal of the cosine function. Therefore, \(\sec \theta = \frac{1}{\cos \theta}\). Given: \[ \sec \theta = \frac{2\sqrt{3}}{3} \] Then: \[ \cos \theta = \frac{3}{2\sqrt{3}} = \frac{\sqrt{3}}{2} \] We need to find the angle \(\theta\) whose cosine is \(\frac{\sqrt{3}}{2}\). Checking standard angles: - \(\cos 30^\circ = \frac{\sqrt{3}}{2}\) - \(\cos 150^\circ = -\cos 30^\circ = -\frac{\sqrt{3}}{2}\) So, the correct answer from the given options is: \[ \boxed{30^\circ} \]

Calculus: Early Transcendentals
8th Edition
ISBN:9781285741550
Author:James Stewart
Publisher:James Stewart
Chapter1: Functions And Models
Section: Chapter Questions
Problem 1RCC: (a) What is a function? What are its domain and range? (b) What is the graph of a function? (c) How...
icon
Related questions
Question
### Mathematics Exercise: Trigonometric Functions

#### Question:

Evaluate the following using exact degree measure. Show all of your work.

\[ \sec^{-1} \left( \frac{2\sqrt{3}}{3} \right) \]

#### Multiple Choice Answers:
- [ ] 60°
- [ ] 150°
- [ ] 30°
- [ ] 120°

#### Explanation:

To solve the given problem, recall that the secant function is the reciprocal of the cosine function. Therefore, \(\sec \theta = \frac{1}{\cos \theta}\).

Given:
\[ \sec \theta = \frac{2\sqrt{3}}{3} \]

Then:
\[ \cos \theta = \frac{3}{2\sqrt{3}} = \frac{\sqrt{3}}{2} \]

We need to find the angle \(\theta\) whose cosine is \(\frac{\sqrt{3}}{2}\). Checking standard angles:

- \(\cos 30^\circ = \frac{\sqrt{3}}{2}\)
- \(\cos 150^\circ = -\cos 30^\circ = -\frac{\sqrt{3}}{2}\)

So, the correct answer from the given options is:

\[ \boxed{30^\circ} \]
Transcribed Image Text:### Mathematics Exercise: Trigonometric Functions #### Question: Evaluate the following using exact degree measure. Show all of your work. \[ \sec^{-1} \left( \frac{2\sqrt{3}}{3} \right) \] #### Multiple Choice Answers: - [ ] 60° - [ ] 150° - [ ] 30° - [ ] 120° #### Explanation: To solve the given problem, recall that the secant function is the reciprocal of the cosine function. Therefore, \(\sec \theta = \frac{1}{\cos \theta}\). Given: \[ \sec \theta = \frac{2\sqrt{3}}{3} \] Then: \[ \cos \theta = \frac{3}{2\sqrt{3}} = \frac{\sqrt{3}}{2} \] We need to find the angle \(\theta\) whose cosine is \(\frac{\sqrt{3}}{2}\). Checking standard angles: - \(\cos 30^\circ = \frac{\sqrt{3}}{2}\) - \(\cos 150^\circ = -\cos 30^\circ = -\frac{\sqrt{3}}{2}\) So, the correct answer from the given options is: \[ \boxed{30^\circ} \]
Expert Solution
steps

Step by step

Solved in 3 steps with 3 images

Blurred answer
Recommended textbooks for you
Calculus: Early Transcendentals
Calculus: Early Transcendentals
Calculus
ISBN:
9781285741550
Author:
James Stewart
Publisher:
Cengage Learning
Thomas' Calculus (14th Edition)
Thomas' Calculus (14th Edition)
Calculus
ISBN:
9780134438986
Author:
Joel R. Hass, Christopher E. Heil, Maurice D. Weir
Publisher:
PEARSON
Calculus: Early Transcendentals (3rd Edition)
Calculus: Early Transcendentals (3rd Edition)
Calculus
ISBN:
9780134763644
Author:
William L. Briggs, Lyle Cochran, Bernard Gillett, Eric Schulz
Publisher:
PEARSON
Calculus: Early Transcendentals
Calculus: Early Transcendentals
Calculus
ISBN:
9781319050740
Author:
Jon Rogawski, Colin Adams, Robert Franzosa
Publisher:
W. H. Freeman
Precalculus
Precalculus
Calculus
ISBN:
9780135189405
Author:
Michael Sullivan
Publisher:
PEARSON
Calculus: Early Transcendental Functions
Calculus: Early Transcendental Functions
Calculus
ISBN:
9781337552516
Author:
Ron Larson, Bruce H. Edwards
Publisher:
Cengage Learning