Chapter 8: Problem 9
Use a calculator to find an approximate value of each expression correct to five decimal places, if it is defined. (a) \(\sin ^{-1}(0.13844)\) (b) \(\cos ^{-1}(-0.92761)\)
Short Answer
Expert verified
(a) \( \sin^{-1}(0.13844) \approx 0.13879 \) radians; (b) \( \cos^{-1}(-0.92761) \approx 2.76109 \) radians.
Step by step solution
01
Understanding Inverse Sine Function
The inverse sine function, denoted as \( \sin^{-1}(x) \), is used to find the angle whose sine value is \( x \). The range of \( \sin^{-1}(x) \) is between \( -\frac{\pi}{2} \) and \( \frac{\pi}{2} \) radians or \(-90\) to \(90\) degrees.
02
Compute \( \sin^{-1}(0.13844) \) Using Calculator
To find \( \sin^{-1}(0.13844) \), enter the value \( 0.13844 \) into the calculator and use the inverse sine function (usually labelled as \( \sin^{-1} \) or \( \arcsin \)). The calculator provides the output in radians unless set to degrees.
03
Round the Value to Five Decimal Places
Once you obtain \( \sin^{-1}(0.13844) \), round the result to five decimal places. The approximate value in radians is 0.13879.
04
Understanding Inverse Cosine Function
The inverse cosine function, denoted as \( \cos^{-1}(x) \), finds the angle whose cosine is \( x \). The range of \( \cos^{-1}(x) \) is from \( 0 \) to \( \pi \) radians or \(0\) to \(180\) degrees.
05
Compute \( \cos^{-1}(-0.92761) \) Using Calculator
To find \( \cos^{-1}(-0.92761) \), enter the value \( -0.92761 \) into the calculator and use the inverse cosine function (typically labeled as \( \cos^{-1} \) or \( \arccos \)). The answer will be provided in radians.
06
Round the Value to Five Decimal Places
After computing \( \cos^{-1}(-0.92761) \), round the result to five decimal places. The approximate value in radians is 2.76109.
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Inverse Sine Function
The inverse sine function, often represented as \( \sin^{-1}(x) \) or "arcsine," helps us determine the angle whose sine equals \( x \). This function is essential for solving equations where the sine value is known, but the angle is not.
- It is crucial to understand its limited range, which spans from \( -\frac{\pi}{2} \) to \( \frac{\pi}{2} \) in radian measure. This converts to angles between \(-90\) and \(90\) degrees.
- When dealing with the inverse sine function on a calculator, ensure your device is set to the desired unit (radians or degrees), as the outputs depend on this.
- In terms of usage, type the known value (like \(0.13844\)) into the calculator and apply \( \sin^{-1} \) to find the corresponding angle.
- Remember to round the results to the required decimal places for precision, especially in academic exercises.
Inverse Cosine Function
The inverse cosine function, denoted as \( \cos^{-1}(x) \) or "arccosine," serves to find the angle for a known cosine value. This is particularly useful in trigonometric equations where the angle in question is not immediately known.
- It has a natural range from \( 0 \) to \( \pi \) radians, which translates to the angles ranging from \(0\) to \(180\) degrees.
- To effectively use a calculator for this function, first ensure it is in the correct mode (degrees or radians), based on your need. This ensures the results are in the desired format.
- Insert the cosine value, such as \(-0.92761\), into your calculator and apply the \( \cos^{-1} \) function.
- Accuracy is key, so make sure to round the result appropriately to five decimal places if specified by the problem.
Radian Measure
Radians are a way to measure angles, fundamentally connected to the unit circle. They offer a more natural way in mathematics to describe angles compared to degrees.
- In mathematics, the circumference of a circle is \(2\pi\), meaning the entire circle is \(2\pi\) radians.
- This implies that \( \pi \) radians correspond to \(180\) degrees, establishing the crucial conversion factor: \(1\) radian equals approximately \(57.2958\) degrees.
- Many mathematical calculations, particularly in calculus and trigonometry, prefer radians due to their seamless integration with the circle's properties.
- Understanding how to convert between radians and degrees is vital, as it ensures precise and accurate results when working with trigonometric and geometric functions.