7. Find the value of sin (a - B) if tan a 0° a 90°, and 0°

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...
Question
**Trigonometry Problem**

**Problem Statement:**

7. Find the value of \( \sin (\alpha - \beta) \) if \( \tan \alpha = \frac{4}{3} \), \( \cot \beta = \frac{5}{12} \), with the conditions \( 0^\circ < \alpha < 90^\circ \) and \( 0^\circ < \beta < 90^\circ \).

**Solution Approach:**

To find \( \sin (\alpha - \beta) \), we need to use the trigonometric identity:

\[
\sin (\alpha - \beta) = \sin \alpha \cos \beta - \cos \alpha \sin \beta
\]

Given:
- \( \tan \alpha = \frac{4}{3} \) implies a right triangle where the opposite side is 4, the adjacent side is 3, and the hypotenuse is \( \sqrt{4^2 + 3^2} = 5 \). Therefore:
  - \( \sin \alpha = \frac{4}{5} \)
  - \( \cos \alpha = \frac{3}{5} \)

- \( \cot \beta = \frac{5}{12} \) implies a right triangle where the adjacent side is 5, the opposite side is 12, and the hypotenuse is \( \sqrt{5^2 + 12^2} = 13 \). Therefore:
  - \( \sin \beta = \frac{12}{13} \)
  - \( \cos \beta = \frac{5}{13} \)

Plugging these into the identity:

\[
\sin (\alpha - \beta) = \left( \frac{4}{5} \times \frac{5}{13} \right) - \left( \frac{3}{5} \times \frac{12}{13} \right)
\]

Simplifying:

\[
= \left( \frac{20}{65} \right) - \left( \frac{36}{65} \right) 
= \frac{20 - 36}{65} 
= \frac{-16}{65}
\]

Hence, the value of \( \sin(\alpha - \beta) \) is \( \frac{-16}{65} \).
Transcribed Image Text:**Trigonometry Problem** **Problem Statement:** 7. Find the value of \( \sin (\alpha - \beta) \) if \( \tan \alpha = \frac{4}{3} \), \( \cot \beta = \frac{5}{12} \), with the conditions \( 0^\circ < \alpha < 90^\circ \) and \( 0^\circ < \beta < 90^\circ \). **Solution Approach:** To find \( \sin (\alpha - \beta) \), we need to use the trigonometric identity: \[ \sin (\alpha - \beta) = \sin \alpha \cos \beta - \cos \alpha \sin \beta \] Given: - \( \tan \alpha = \frac{4}{3} \) implies a right triangle where the opposite side is 4, the adjacent side is 3, and the hypotenuse is \( \sqrt{4^2 + 3^2} = 5 \). Therefore: - \( \sin \alpha = \frac{4}{5} \) - \( \cos \alpha = \frac{3}{5} \) - \( \cot \beta = \frac{5}{12} \) implies a right triangle where the adjacent side is 5, the opposite side is 12, and the hypotenuse is \( \sqrt{5^2 + 12^2} = 13 \). Therefore: - \( \sin \beta = \frac{12}{13} \) - \( \cos \beta = \frac{5}{13} \) Plugging these into the identity: \[ \sin (\alpha - \beta) = \left( \frac{4}{5} \times \frac{5}{13} \right) - \left( \frac{3}{5} \times \frac{12}{13} \right) \] Simplifying: \[ = \left( \frac{20}{65} \right) - \left( \frac{36}{65} \right) = \frac{20 - 36}{65} = \frac{-16}{65} \] Hence, the value of \( \sin(\alpha - \beta) \) is \( \frac{-16}{65} \).
Expert Solution
steps

Step by step

Solved in 2 steps with 2 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