Skip to main content
Ch. 3 - Radian Measure and The Unit Circle
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161, 9780135440780, 9780136881117, 9780135440827, 9780135924891Non è quello che usi tu?Cambia libro di testo
Capitolo 4, Problema 62

Find the approximate value of s, to four decimal places, in the interval [0, π/2] that makes each statement true.


cos s = 0.7826

Guida verificata passo dopo passo
1
Identify the problem: We need to find the value of \( s \) in the interval \( [0, \frac{\pi}{2}] \) such that \( \cos s = 0.7826 \).
Recall the inverse cosine function: To find \( s \), we use the inverse cosine (arccos) function, which gives \( s = \arccos(0.7826) \).
Apply the inverse cosine: Use a calculator or a computational tool to find \( s = \arccos(0.7826) \). Make sure your calculator is set to radians since the interval is given in radians.
Round the result: After calculating \( s \), round the value to four decimal places as requested.
Verify the solution: Check that the value of \( s \) lies within the interval \( [0, \frac{\pi}{2}] \) and that \( \cos s \) is approximately 0.7826 to confirm correctness.

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.

Inverse Trigonometric Functions

Inverse trigonometric functions allow us to find the angle when the value of a trigonometric ratio is known. For example, to find s such that cos s = 0.7826, we use the arccos (cos⁻¹) function, which returns the angle whose cosine is 0.7826.
Video consigliato:
Percorso guidato
4:28
Introduction to Inverse Trig Functions

Domain and Range of Cosine and Arccosine

The cosine function outputs values between -1 and 1 for angles in radians. Its inverse, arccos, returns angles in the range [0, π]. Since the problem restricts s to [0, π/2], the solution must lie within this interval, ensuring the angle corresponds to the first quadrant.
Video consigliato:
Percorso guidato
4:22
Domain and Range of Function Transformations

Rounding and Approximation

When calculating trigonometric values, results often need to be rounded to a specified number of decimal places. Here, the angle s must be approximated to four decimal places, which requires careful use of a calculator or software to ensure precision and accuracy.
Video consigliato:
Percorso guidato
4:45
How to Use a Calculator for Trig Functions